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GAL 1 L 










** Sempre il novo che & grande appar menzogna 
. . . al volgar debile ingegno ; 
Ma imperturbato il regno 
De' saggi dietro all'utile s'ostina. 
Minaccia n& vergogna 
No '1 frena, no '1 rimove ; 
Prove accumula a prove ! 
Del popolare error 1' idol rovina, 
E la salute ai posteri destina." 

PARINI : " L'Innesto del Vaiuolo." 

"Anything new, which is great, appears false to the ordinary weak mind, but 
the rule of the wise obstinately continues its way unmoved. Neither threats nor 
shame checks or changes its course ; experiment follows experiment ; the idol of 
popular error is throAvn down, and health to posterity is ensured." 














THE history of the life and labours of Galileo is 
pregnant with a peculiar interest to the general 
reader as well as to the man of science and the 
philosopher His brilliant discoveries the man of 
science regards as his peculiar property ; the means 
by which they were made and the development 
of his intellectual character belong to the logician 
and the philosopher ; but the triumphs and reverses 
of his eventful life must be claimed for our common 
nature, as subjects of deep interest and serious 

So wrote Sir David Brewster in the opening 
paragraph of his biography of Galileo (" Martyrs of 
Science," London, 1841). It is the object of the 
present volume to give a fuller presentation, under 
this three-fold aspect, of the life which Sir David 
has only outlined. 

In recent years materials for such a work have 
been brought together which were not accessible 


when Brewster wrote. Imperfect collections of 
Galileo's writings were published in Bologna 1656, 
in Florence 1718, in Padua 1744, and in Milan in 
1 808- 1 1 and 1832 ; but the first edition of anything 
approaching a complete character is that of Albri 
in sixteen volumes, which was begun in 1842 and 
completed in 1856. That even this collection is 
defective in many important particulars is shown 
by the fact that another edition was begun in 1890, 
under the auspices of the King of Italy, and under 
the direction of Professor Antonio Favaro of the 
Royal University of Padua. Of this monumental 
work, twelve out of twenty large volumes have 
appeared. They contain all Galileo's works, the 
works of adversaries annotated by him, and his 
correspondence down to the year 1619, and supply 
an inexhaustible mine for the student of science. 
In exploring this for nuggets I have had the in- 
estimable assistance of Professor Favaro, who has 
given me many valuable hints, and has generously 
placed at my disposal all his Galilean studies and 
researches for the last twenty-five years. Thus I 
am enabled to give a fuller and more comprehensive 
history of the life and work of Galileo than has 
hitherto been attempted, or, indeed, been possible. 
Thanks mainly to Professor Favaro and his multi- 


tudinous writings, my book contains much new 
matter, and, what is more important, it avoids most, 
if not all, of the numerous errors and fables which 
previous biographers have little by little woven 
into the life of Galileo. 

For the benefit of students who may wish to 
explore for themselves (and I promise them rich 
harvests), I have given at the end of this volume 
a short history of Galileo's writings, followed by 
a list of works which I have consulted, and which 
may be found useful. Speaking for myself, I have 
to acknowledge my special indebtedness to (besides 
the editions of Albri and Favaro) the works of 
Nelli, Venturi, and Drinkwater, and, coming down 
to more recent times, those of Martin, Olney, 
Von Gebler, and Favaro. The works of Nelli, 
Venturi, Drinkwater, and Martin have been useful 
to me in a general way. Mrs Olney's charming 
volume and Favaro's " Galileo e Suor Maria Celeste " 
have been largely drawn upon for Galileo's private 
life, and for his correspondence with his daughter ; 
while Martin, Von Gebler, and Favaro have been 
the chief guides in my account of Galileo's relations 
with the Roman Curia. 

I have also to acknowledge my indebtedness to 
Mr Arthur Berry, of King's College, Cambridge, 


who very kindly read the proofs and made sugges- 
tions of great value, which I was happy to adopt, and 
to Mr H. H. Champion, The School, Uppingham, 
for revising the scientific parts of my work. Mr 
Champion not only corrected a few errors and 
ambiguities into which I had fallen, but supplied 
most of the material on which my rksum&s of the 
Dialogues of 1632 and 1638 are based. 

In my quotations of letters and documents I do 
not in all cases give them in full. I mostly content 
myself with extracts of the parts referable to the 
particular matter in hand. I think it necessary to 
point this out, as the quotations do not always 
show where the ellipses occur. 




PISA (1 564-1 589) I 

II. GALILEO, PROFESSOR IN PISA (1589-1592) ... 22 

III. GALILEO, PROFESSOR IN PADUA (1592-1610) . . 34 


tinued 59 

V. GALILEO, PROFESSOR IN PADUA (1592-1610) con- 
tinued ......... 74 

cluded 98 


(1610-1612) 116 

(l6l2-l6l7) 146 

IX. GALILEO IN FLORENCE (1617-1624) .... 178 


(1624-1629) 204 



THE INQUISITION (1632-1633) .... 263 

tinued 294 







ON THE TWO NEW SCIENCES (1634-1636) . . 338 



BIBLIOGRAPHY ........ 433 


INDEX 447 


PORTRAIT OF GALILEO IN 1635, AGED 72 . . Frontispiece 

From Sustermans* picture in Uffizi Gallery, Florence 
(Alinari Photo]. 


From photograph by Alinari , Florence, 


From a drawing "by A. H, Hallam Murray. 


From photograph by Alinari, Florence, 




GALILEO ....... To face page 34 

From Favartfs paper in " Natura ed Arte" Milan % 1833. 


From Favaro's *' Terzo Centenario di Galileo in Padova" 
Florence^ 1892* 


From Favaro's paper in " Natura ed Arte" Milan^ iSqj* 


From Nelli's " Vita c Commerdo Letter ario di GalUeo" 
Lausanne^ 1793. 

From Favaro's paper in "Natura ed Arte" Milan, 1893. 


From Favaro's " Terzo Centenario di Galileo in Padova^' 

From pftotographby Alinari, Florence, 




From lt Terzo Centenario di Galileo in Padova> " 
Florence, 1892. 



From Fawtro's " Intorno ai Cannocchiali di Galileo" 
Venice, igox. 


From Favaro's "Intorno alia Apparenza di Saturno 
osseruata da Galileo" Venice^ TQOI. 


From Huygen? < Sy sterna Saturnium" The Hague, 1659. 


From photograph by Alinari> Florence, 


From Ventures " Memorie e Lettere di Galileo" Modena> 

From old engraving tempo Galileo. 


PORTRAIT OF GALILEO, AGED ABOUT 75 . . To face page 384 

From a copy of the picture (Sustermans* School) in the 
Pitti Collection , Florence^ photographed by Alinari, 


From Favaro's " Galileo e Cristiano Huygens. Nuom 
documentisuW applicazione delpendolo alt orologio" 
(" Nuovi studi Galileiani" Venice, 1891). 

From photograph by Alinari^ Florence* 

From photograph by Alinari, Florence, 





GALILEO GALILEI, one of the earliest and, perhaps, 
one of the greatest of the experimental philosophers 
of the modern world, and the father of telescopic 
astronomy, is generally known in history by his 
baptismal name, Galileo, alone, in accordance with 
a custom of the Italians to call their great men 
by their Christian names, or by nicknames derived 
from some peculiarity of the individual or from the 
place of his birth. 

Galileo, as we shall continue to call him, was 
descended from a noble family of Florence, which 
was long and honourably connected with the govern- 
ing bodies of the republic, fourteen of its members 
having filled the highest posts on nineteen different 
occasions between the years 1343 and 1528. 

The original surname of the family, Bonajuti, 
was exchanged for that of Galilei on the election, 


2 EARLY YEARS [1564- 

in 1343, of one of its members, Tommaso, to the 
College of the XII Buonomini, or the Twelve Good 
Men, as the ruling body of the republic was then 
called. A grandson of this Tommaso, christened 
Galileo, became a celebrated physician, and, in 
1438, was appointed Professor of Medicine in the 
University of Florence. He was elected one of the 
Priori, or governing body, on two occasions, in 
1430 and 1434; and in 1445 he filled the office of 
Gonfaloniere or Chief Magistrate of the republic. 

After a long and well-spent life he was buried 
with public honours in the Church of Santa Croce, 
Florence, where his grave is marked by a slab of 
white marble let into the floor of the nave, near the 
main entrance door. The stone bears a full-length 
figure in bas-relief of an old man, robed, and wearing 
the high folded cap used by the gentle folk and 
scholars of the period. On the breast lies a closed 
book, over which the hands are folded, and at the 
feet is a Latin inscription, setting forth that "This 
Maestro Galileo of the Galilei (formerly of the 
Bonajuti) was in his time the head of Philosophy 
and Medicine, who also in the highest magistracy 
loved the republic marvellously. His son, Benedetto, 
blest in the inheritance of his holy memory and 
well-spent and pious life, has appointed this tomb 
for his father, for himself, and for his posterity." l 

Vincenzio, the father of our Galileo, was an 
impoverished descendant of this noble house, 
being the great-grandson of Michelangelo Galilei, 

1 Ruskin, "Mornings in Florence," p. 14, speaks of this as "one of 
the most beautiful pieces of Fourteenth (? Fifteenth) century sculpture 
in this world," 


a brother of the above-named Maestro Galileo, and 
twice one of the Priori, in 1431 and 1438. 

Vincenzio was born in 1520, and though, as we 
have just said, of broken fortune, he was well 
endowed on the intellectual side. He studied 
music under Zarlino of Chioggia, a seaport town 
fifteen miles south of Venice ; but in after years he 
did not hesitate to attack the opinions of his old 
master in his " Dialogo della Musica Antica et 
della Moderna" (Florence, 1581), and c< Discorso 
intorno alle opere di Gioseffo Zarlino" (Florence, 

I589). 1 

These works display great knowledge and 
laborious research ; and the first-named, especially, 
has been of much assistance to the musical historian 
of later days. One passage from the introduction 
may fittingly be noted here, as it shows the same 
spirit of free enquiry free from authority and 
tradition which pervades all the acts and writings 
of his distinguished son. 

" It appears to me," he says, " that they who in 
proof of any assertion rely simply on the weight 
of authority, without adducing any argument in 
support of it, act very absurdly. I, on the contrary, 
wish to be allowed freely to question and freely 
to answer without any sort of adulation, as well 
becomes those who are sincerely in search of 

Besides writing learnedly on the theory and 
practice of music, Vincenzio was especially distin- 

1 These and four other works of the same author are enumerated 
in Favaro's " Bibliografia Galileiana," Rome, 1896. Other essays, 
which were never printed, are now preserved among the Galileo MSS. 
in the National Library, Florence. 

4 EARLY YEARS [1564- 

guished as an exquisite performer on the lute an 
instrument which he tells us was then better manu- 
factured in England than in any other part of 
Europe. He was also a skilful mathematician, and 
had an extensive acquaintance with the languages 
and literatures of Greece and Rome. 

By his wife, Giulia Ammannati of Pescia, 
Vincenzio had three sons, Galileo, Michelangelo, 
and Benedetto, the last of whom died in infancy ; 
and four daughters, Virginia, Anna, Livia, and 
Lena. Of Anna we know nothing, and of Lena 
very little. 

Galileo, the eldest, was born in Pisa, where his 
father was engaged in commerce, on I5th February 
1564 just three days before his famous fellow- 
countryman, Michelangelo Buonarroti, closed his 
eyes in Rome. 

The first decade of Galileo's life, that is, down 
to about 1575, was passed at Pisa, where, in the 
frequent absences of the father on business, the 
family lodged with a relative named Muzio 
Tedaldi. In Pisa, then, and not in Florence as 
has hitherto been supposed, Galileo received his 
early education, partly at the school of one 
Jacopo Borghini, and partly at home, where his 
father helped him with his Greek and Latin 

At about the age of twelve or thirteen Galileo 
was transferred to the far-famed monastery of 
Vallombrosa, near Florence, to go through a 
course of what,, according to the time, constituted 
"the Humanities," or the literary education then 
considered indispensable for a well-born youth. 

Supposed Birthplace of Galileo, in Pisa. 


Here he made himself acquainted with the best 
Latin authors, and also acquired a fair command 
of the Greek tongue, thus laying the foundation of 
the elegant and incisive style for which his writings 
are so distinguished. With one of the monks he 
began a course of instruction in logic, but from the 
first he appears to have had little taste for this 
subject, preferring what .scraps of elementary science 
and philosophy he could pick out of the lessons. 

From a contemporary document, first published 
by Professor Selmi in I864, 1 it would seem that, 
while with the monks of Vallombrosa, Galileo was 
so far attracted towards a religious life as to have 
joined the novitiate of the Order ; but his father, 
who had other designs for him, seized the oppor- 
tunity of an attack of ophthalmia, and withdrew the 
boy from the monastery. A letter of Muzio Tedaldi 
to Vincenzio Galilei, dated i6th July 1579, and 
congratulating him on the removal of his son, seems 
to corroborate this story, and fixes the date with 
sufficient accuracy. 

This lovely spot has for English readers another 
and more personal recollection. The Florentines 
are proud to this day to remind one that our Milton 
visited it more than once during his stay in Florence 
in the autumn of 1638 and the spring of 1639. It 
was with these visits in her mind that Elizabeth 
Barrett Browning wrote : 

" Remembering Vallombrosa. Therefore is 
The place divine to English man and child, 
And pilgrims leave their soul here in a kiss." 

It lies, as the name Vallombrosa imports, in a 

1 "Nel Trecentesimo Natalizio di Galileo," Pisa, 1864. 

6 EARLY YEARS [1564- 

shady and sequestered vale. Hence Milton's lines 
descriptive of Satan calling : 

" His legions, angel forms, who lay entranced, 
Thick as autumnal leaves that strow the banks 
In Vallombrosa, where the Etrurian shades 
High over-arched imbower." 

Paradise Lost^ Book I. lines 301-4. 

We have said that in withdrawing his son from 
Vallombrosa Vincenzio Galilei had other designs 
for him ; but at first they -were not very ambitious. 
Vincenzio, although of noble birth, had no property, 
his income from trade was scanty and precarious, 
and his family was large. Under these circum- 
stances he destined his son to a career by no means 
distinguished, though one that conferred wealth on 
Florence, and therefore held in no small esteem by 
her citizens the boy was to be a cloth-dealer. 

Now it must be told that from his early boyhood 
Galileo was remarkable for intellectual aptitudes of 
various kinds, coupled with considerable mechanical 
inventiveness. His favourite pastime was the con- 
struction of toy-machines, not the less ingenious 
because they did not always work. 1 As he grew up 
he learnt from his father something of the theory 
and practice of music, and became so skilful with 
the lute as to excel him, good performer as he was, 
" in charm of style and delicacy of touch. " He was 
also, it is said, a creditable performer on the organ 
and one or two other instruments, but the lute was 
his favourite, and continued to be so through life. 
As he found it a pleasure in youth, so it was a great 

1 It is interesting to note that Newton showed a similar precocity 
for things mechanical. 

Monastery of Vallombrosa. 

[To face fa 6. 


solace in his later years especially when blindness 
was added to his other afflictions. 

In the sister art his talent was equally striking, 
and as a lad he showed considerable skill in drawing 
and painting. In later life he used to tell his 
friends that, had circumstances permitted him to 
choose his own career, he would have elected to 
become a painter. So well known was his youthful 
talent as draughtsman and colourist that such 
acknowledged artists as Ludovico Cigoli, Bronzino, 
Passignano, and Jacopo da Empoli, often sought his 
criticism of their works. Cigoli, in particular, was 
wont to say that Galileo alone had been his teacher 
in the art of perspective, and that whatever credit 
he enjoyed as a painter was owing to his advice and 

In his youthful days Galileo was also very fond 
of poetry, and later on in these pages we shall have 
occasion to notice his essays on Dante, Ariosto, and 
Tasso, as well as some verses and the fragment of 
a play, all of which bear witness to, at least, a 
cultivated taste. 

In view of these great and varied abilities thus 
early displayed (to which we must not forget to add 
a good knowledge of Greek and Latin), the father 
could not help concluding that his son was born to 
be something better than a seller of cloths, and he 
now resolved upon a scientific career. As, however, 
it was necessary that the branch selected should 
offer a prospect of profit, and as he had himself had 
experience of the unremunerativeness of mathe- 
matics and music, the profession of medicine was 
decided on. Accordingly, on 5th September 1581, 

8 EARLY YEARS [1564- 

when seventeen and a half years old, Galileo was sent 
to study medicine at the University of Pisa. 1 As 
before this time the family had returned to Florence 
the youth was placed as a boarder in the house of 
the relative before mentioned, Muzio Tedaldi, and at 
once took up the usual courses in philosophy and 
medicine, his teacher in the latter being Andrea 
Cesalpino, the celebrated physician and botanist, who 
filled the chair of medicine from 1567 to 1592. 

Viviani, the first biographer of Galileo, and his 
last and best-loved disciple, tells us that our youth's 
attitude from the first in the philosophical classes was 
not at all to the satisfaction of his teachers, owing 
to the habit, inherited or acquired from his father, 
of examining an assertion to see what it was worth, 
instead of blindly accepting it on faith in the master, 
or in deference to authority. 2 In consequence of 
this unheard-of audacity in one so young, he soon 
acquired a reputation among the professors and his 
fellow - students for bold contradiction, and was 
dubbed " The Wrangler/' His eager questioning 
of the dictates of Aristotle, Plato, St Thomas 
Aquinas, and other ancient lights, found no favour 
in their eyes. To the narrow conceptions of the 
time, a philosopher needed only to know Aristotle 

1 In order to reduce the expenses of a college training, Vincenzio 
tried to obtain for his son one of the forty free foundations for 
necessitous students attached to the University, but neither then, nor 
at the end of the third year, when the request was renewed, was the 
favour granted. 

2 In the first volume of Favaro's edition of Galileo's works, there 
are many pages of Juvenilia, or Commentaries (in Latin) on Aristotle's 
"de Caelo" and "de Mundo," which were written about 1584, and 
which are evidently notes of lectures he had been attending. They 
show the close attention of the young student. 


by heart ; to understand hint was a secondary con- 
sideration ; to contradict him was a blasphemy. 
Galileo, however, would try to understand, and often 
dared to contradict, and thus arose that feeling of 
hostility which ultimately, as we shall see, drove 
him from Pisa, and which endured for years after 
he became famous. 1 

In 1581 Galileo made his first discovery, which 
is characteristic of his observant eye. As the story 
goes, the student of eighteen was one afternoon 
performing his devotions in the Cathedral of Pisa, 
and in full view of Maestro Possenti's beautiful 
bronze lamp which hung (and still hangs) from the 
roof of the nave. In order to light it more easily 
the attendant drew it towards him, and then let it 
swing back. Galileo at first observed this simple 
incident, as thousands of othei worshippers had 
done before him and have done since, i.e. in a 
casual way, but quickly his attention became riveted 
to the swinging lamp. The oscillations, which were 
at first considerable became gradually less and less, 
but, notwithstanding, he could see that they were 
all performed in the same time, as he was able to 
prove by timing them with his pulse the only 
watch he possessed! 2 

1 Thus, Father Castelli, the first disciple and lifelong friend of 
Galileo, writing to him from Pisa in November 1613, says: "Of our 
controversies (on the earth's motion) not a word is allowed to be said 
a thing which astonishes me. Your marvellous discoveries are 
scarcely known here even by name." 

54 Whether this be only a pretty fable, like that of Newton and the 
apple, cannot now be decided, but it is, at least, certain that Possenti's 
lamp was not the one which Galileo observed, since it was not made 
until 1587, and was only hung in its present place on the 2Oth 
December in that year. 

io EARLY YEARS [1564- 

After some experiments at home, he saw that an 
instrument might be constructed on this principle 
which should mark with accuracy the rate and 
variation of the pulse. He gave shape to the idea, 
and, imperfect though the instrument was, it was 
received with wonder and delight by the physicians 
of the day, and was long in general use under the 
name of Pulsilogia. Santorio, who was Professor 
of Medicine at Padua, has given representations of 
four different forms of this instrument (in his 
" Method! Vitandorum Errorum in Arte Medica," 
Venice, 1607), three of which we reproduce. 

Fig. i consists merely of a weight at the end of 
a string, which is held at the top of a graduated 
scale. The string being gathered up into the 
hand till the vibrations of the weight coincide 
with the beatings of the patient's pulse, the length 
is ascertained from the scale, which if great 
indicates a languid, and if small, a more lively 
action. In Fig. 2 the improvement is introduced 
of connecting the scale and string; the length of 
the latter is regulated by turning a peg, and a 
bead on the string shows the measure* Fig. 3 
is still more compact, the string being adjusted by 
winding (or unwinding) upon an axle at the back 
of the dial-plate. More than half a century later, 
as we shall see in the course of our narrative, 
Galileo utilised the same principle of the pendulum 
in the design of an astronomical clock. 

Up to the time of which we are treating, the 
study of mathematics, although mentioned in the 
rotuli of the schools, was practically neglected 
in Italy. The names of Euclid and Archimedes 

I>ossenti 1 s Lamp iu the Cathedral, Pisa. 

{To face j. 10. 




were little more than empty sounds to the students 
who thronged the lecture halls of Pisa, of Bologna, 
and even of learned Padua. Furthermore, Galileo's 





Fig. 2. 

Kg. 3. 



father, thinking that such studies by one intended 
for the medical profession would be a waste of 



time, not only abstained from teaching the boy 
what he knew himself, but endeavoured to prevent 
his obtaining the knowledge from other sources, 
assuring him that it would be time enough when 
his medical studies were finished. Thus, up to 
the close of his nineteenth year, Galileo knew little 
or nothing of mathematics. But 

"There's a divinity that shapes our ends, 
Rough-hew them as we will." 

The natural and as yet hardly suspected bent 
of the young man's mind now asserted itself, and 
in a way not to be mistaken. 

During the winter and spring of 1582-83 the 
Court of Tuscany, according to custom, was resid- 
ing at Pisa, and among the suite was one Ostilio 
Ricci, an able mathematician, tutor to the Grand- 
ducal pages, and a friend of Galileo's family in 
Florence. Naturally, the tutor and the young 
student became friends. Going on one occasion to 
pay Ricci a visit, Galileo found him engaged in 
giving a lesson to the pages on some problems in 
Euclid. He did not enter, but, standing behind the 
door, followed the lesson with a strange attention. 
This was the beginning of a new sensation, a 
craving of the intellect, under the influence of 
which he found himself drawn repeatedly to the 
pages' class-room. Each time, entering unobserved 
and concealing himself behind a door, he listened, 
Euclid in hand, to the teacher's demonstrations, 
Henceforth mathematics were more studied than 
medicine, for which, truth to say, he never had 
any relish. Then, taking courage and confessing 
his sin of curiosity, he begged the astonished 

I5 8 9 ] MATHEMATICS 13 

tutor to help him, which Ricci readily consented 
to do. 1 

When Vincenzio learnt, as he did through Ricci, 
that his son was devoting himself to Euclid to the 
neglect of Hippocrates and Galen, he did his 
utmost to divert the young man from this (as it 
seemed to him) unprofitable study, 2 But in the end 
old Vincenzio had to learn the unconquerable power 
of genius, and had to submit to it, just as the father of 
the great Michelangelo had to submit, and under very 
similar circumstances, one hundred years before. 

Vincenzio's consent was probably hastened by 
other considerations. With his large family and 
small means he must have found it increasingly 
difficult to keep his son at college. At any rate, 
at the end of the third year (1584) he again peti- 
tioned the Grand Duke, Ferdinando I., for one of 
the forty free places founded in aid of poor scholars ; 
but, owing to the hostility (to which we have already 
referred) caused by "The Wrangler's" general 
attitude and his marked disrespect for " authority/' 
the petition was refused. Thereupon, after nearly 
four years' residence, and without taking the 
doctor's degree, Galileo was withdrawn from the 
University, and returned to the parental roof in 
Florence. This would be about the summer of 


Professor Favaro, the latest and most accurate of Galileo's 
biographers, is inclined to doubt this story, but, as they say in Italy, 
Se non I vero^ t ben trovato. 

2 Vincenzio's horror of mathematics or pure science as a means of 
obtaining a living is justified by the fact that while the Professor of 
Medicine in the University of Pisa received 2000 scudi a year, the 
Professor of Mathematics had only 60 (^13) a year, or just 7^d. a 

I 4 EARLY YEARS [1564- 

Here, and chiefly under the guidance of Ostilio 
Ricci, he devoted himself heart and soul to mathe- 
matics and physics. From the study of Euclid he 
passed on to the writings of Archimedes, whose 
work in mechanics he was destined to continue, 
and for whom he then conceived a veneration 'which 
lasted through life. 

In 1586, when fresh from the study of the great 
Syracusan, Galileo constructed the hydrostatic 
balance (la Bilancetta), for ascertaining with 
accuracy the relative weights of any two metals 
in an alloy. His short essay, descriptive of this 
instrument, was circulated in MS. amongst his 
friends, and was published for the first time, after 
his death, in 1644. 

He refers to the popular account of the way 
in which Archimedes detected the fraud committed 
by the goldsmith in the making of Hiero's crown. 
The story is well known, but will bear repeating 
as illustrative of some of the ways of scientific dis- 

" What great things from small may be springing 

Is proved by the engine's deep sob ; 
And yet, after all, the beginning 
Was the kettle that sings on the hob." 

J. E. CARPENTER, Songs. 

Hiero had given a certain weight of gold to be 
made into a crown. When the work was finished 
a suspicion arose in the royal mind that the gold 
had been alloyed with some baser metal, and he 
applied to Archimedes in the hope of detecting the 
supposed imposture. The weight of the crown 
being correct, the problem was to measure its bulk ; 

1589] ARCHIMEDES 15 

for silver being, weight for weight, of greater bulk 
than gold, any alloy of the former, in place of an 
equal weight of the latter, would necessarily increase 
the bulk of the crown. To measure the bulk, the 
only known method for testing the purity of the 
metal, was difficult without melting it into a regular 

Archimedes, after many unsuccessful attempts, 
was about to abandon the search altogether, when 
the following circumstance suggested to his discern- 
ing and prepared mind a train of thought which led 
to the solution of the difficulty. Stepping into his 
bath one day, his mind doubtless fixed on the object 
of his research, he chanced to observe that, the bath 
being full, a quantity of water of the same bulk as 
his body must flow over before he could immerse 
himself. He probably perceived that any other 
body of the same bulk would have displaced the water 
equally ; but that another body of the same weight, 
but less bulky, would not have produced so great an 
effect. In the words of Vitruvius, "as soon as he 
had hit upon this method of detection, he did not 
wait a moment, but jumped joyfully out of the bath, 
and, running forthwith towards his own house, called 
out with a loud voice that he had found what he 
sought. For as he ran he called out in Greek, 
1 Eureka ! Eureka ! ' I have found it out ! I have 
found it out!" When his emotion had sobered 
down, he proceeded to investigate the subject 
calmly. He procured two masses of metal, each of 
equal weight with the crown one of gold, and the 
other of silver ; and having filled a vessel very 
accurately with water, he plunged into it the silver, 

16 EARLY YEARS [1564- 

and marked the exact quantity of water that over- 
flowed. He then treated the gold in the same 
manner, and observed that a less quantity of water 
overflowed than before. He next plunged the 
crown into the same vessel full of water, and 
observed that it displaced more of the fluid than the 
gold had done, and less than the silver, from which 
he inferred that the crown was neither pure gold nor 
pure silver, but a mixture of both. 

Galileo doubted the correctness of this story, for 
he says, the results of such a method are fallacious, 
or, at least, little exact. After much thought on the 
subject, he devised a "most exact " method, which 
he believed was really the one employed by 
Archimedes himself. 


Fig. 4. 

Take a lever AB, Fig. 4, at least a yard long 
(and the longer it is, the more accurate will be its 
indications), delicately suspended from its centre C ; 
and at the ends let there be means of attaching the 
body (say an alloy of gold and silver) to be tested at 
B, and its counterweight at A. First, take a piece 
of pure gold and weigh it in air ; now immerse It 
in water ; it will seem lighter, and the counterpoise 
D must be moved from A to, say, E, to obtain a 
balance. Then, as many times as the space CA 
contains the space AE, so many times is gold 
heavier than water. Proceed in the same way 


with a piece of pure silver. When placed in water, 
it will seem to lose more of its weight than the 
gold did, and its counterpoise will have to be 
moved to, say, F, showing that silver is specifically 
less heavy than gold in the ratio AE to AF. 

Now taking the alloy, it is clear beforehand 
that it will weigh less than an equal volume of 
pure gold, and more than an equal volume of 
pure silver. Weigh it in air and then in water, 
when it will be found that its counterpoise must 
be moved to some point between E and F, say 
G. From this we learn that the weight of gold 
in the mixture is to that of the silver as FG is 
to GE. 

After his work on the hydrostatic balance, 
Galileo undertook an investigation of the centre 
of gravity in solid bodies, the results of which 
were embodied in an essay, 1 which obtained for 
him the title of " The Archimedes of his time/' 
and which, with his previous work on the pendulum, 
the hydrostatic balance, and one or two shorter 
papers, made his name favourably known in Italy. 
Among those to whom he thus became known we 
must here mention one who was ever afterwards 
his warm friend and patron, the Marquis Guidobaldo 
del Monte of Pisaro, already himself a distinguished 
mathematician. Struck by the originality displayed 
in Galileo's essays, Guidobaldo opened a scientific 
correspondence with the author, and took an early 
opportunity of introducing him to the notice of 

1 a Theoremata circa centrum gravitatis solidorum," first circulated 
in MS. copies, and printed in 1638 as an appendix to his " Dialogues 
on Two New Sciences." 


i8 EARLY YEARS [1564- 

Ferdinando L, Grand Duke of Tuscany, as a young 
man of whom the highest expectations might be 

This recognition of his rising talent was, of 
course, very gratifying to the young man, but it 
was a poor substitute for the gains of a practising 
doctor, on which old Vincenzio had calculated, to 
eke out his scanty income. Galileo himself saw 
this, and, with the object of helping to maintain 
his family, he gave private lessons in mathematics 
and mechanics to students in Florence and the 
neighbouring town of Siena. 1 But his great ambi- 
tion was to obtain a professorship in one of the 
Universities, for which Italy was then and still 
is famous. Accordingly, on the Professorship of 
Mathematics in the University of Bologna falling 
vacant (middle of 1587), Galileo made every 
endeavour to secure it, but without success. The 
post was given to Giovanni Antonio Magini, with 
whom we shall meet later on, nominally as a friend 
of our hero, but in reality one of his crassly irre- 
concilable adversaries. 

Late in 1587 Galileo made his first journey to 
Rome, for what purpose history does not say, but 
probably with the object of finding there some 
opening, or in furtherance of his designs on 
the chair at Bologna, which was still vacant, 
Magini's induction dating only from 4th August 

1 About this time, 1587-88, we hear of Galileo reading two papers 
before the Academy of Florence, on the site and dimensions of Dante's 
" Inferno," a subject which just then was being hotly discussed by the 
literati of the Tuscan capital. For this task he was specially chosen 
by Baccio Valori, the president, a fact which shows that his reputation 
as a literary connoisseur was as well established, as that he was an 
able mathematician, 


1588. However this may be, the visit was not 
without result, for it led to his acquaintance with 
Father Cristoforo Clavio, of the Society of 
Jesus, already a celebrated mathematician, and 
to whom the world is mainly indebted for the 
reform of the calendar in 1582. Little did they 
then think that the learned old Jesuit would 
be a stout opponent of the new astronomical 
teachings which the younger man would pro- 
mulgate, but to which, before his death in 1612, 
he was to become a distinguished convert, malgrt 

Evidently while in Rome the two new friends 
had been discussing mathematics, for on his return 
to Florence Galileo sent a letter to Clavio, under 
date, 8th January 1588 (the earliest of his letters 
known to exist), in which he frankly states a 
difficulty respecting the demonstration of a certain 
theorem (lemma). Those, he says, to whom he 
had already submitted it, were not satisfied ; there- 
fore he could not be so himself. In this dilemma, 
he solicits the learned father's opinion, adding that 
if it, too, was unfavourable, he should not rest until 
he had found such a demonstration as would be 
convincing to all. 

Galileo, always anxious to be earning something, 
next applied for the Professorship in Padua Univer- 
sity, rendered vacant by the death of Moletti in 
January 1588, and in this connection he betook 
himself to Venice ; but again he was unsuccessful. 
Soon after, a similar post at Pisa, his Alma Mater, 
became vacant, and, taking advantage of his recent 
introduction to the Grand Duke, in whose gift the 

20 EARLY YEARS [1564- 

appointment was, he applied for it through the 
Marquis del Monte. Once more he was unfortu- 
nate, as the following letter of i6th July 1588 to 
the Marquis shows. 

"My wish regarding Pisa, about which I wrote 
your lordship, will not be carried out; for I hear 
that a certain monk, who lectured there formerly, 
and then, on being made General of his Order, 
retired, has resigned the Generalship, and has 
again taken to lecturing; and that his Highness 
has already appointed him to the post. 

" Now, as here in Florence there was formerly 
a Professorship of Mathematics, which was estab- 
lished by the Grand Duke, Cosimo I., and which 
many among the nobles would like to see revived, 
I have petitioned for it, and hope to obtain it 
through your illustrious brother's influence, to 
whom I have entrusted my case. As there have 
been foreigners here, with whom his Highness has 
been engaged, I have not been able to speak on 
the subject myself, and, therefore, I beg you to 
write again and mention my name/' 

Even in this fourth attempt he failed. Thus 
for nearly two years, from about the middle of 
1587 to the middle of 1589, Galileo saw all his 
efforts to obtain employment in his own country 
end in bitter disappointment Can we wonder 
that, repulsed at Bologna, Rome, Padua, Pisa, and 
Florence, he should turn his thoughts towards the 
East as to a land of promise ? From some documents 
recently brought to light by Professor Favaro, the 
indefatigable editor of the latest collection of 
Galileo's works, it appears that he was actually 
engaged on this desperate enterprise at the moment 
when at last the tide of fortune began to flow in 


his favour. 1 Towards the end of May 1589, 
Galileo and a young Florentine patrician of his 
acquaintance, Ricasoli Baroni, had decided to seek 
together their fortunes in the East, when the 
Mathematical Professorship at Pisa again fell 
vacant. Once more he made application for the 
post, and in due time, and through the joint 
influence of the Marquis Guidobaldo and his 
brother, Cardinal Francesco Maria del Monte, he 
was awarded the prize. This was in July 1589, 
when he was barely twenty-five and a half years 
old. To be sure, the salary was insignificant, only 
60 scudi per annum, or about ^13 of our money. 
Moreover, the appointment was only for three 
years, but renewable. But, any port in a storm; 
and in Galileo's needy circumstances, even this 
wretched salary was not to be rejected ; besides, 
the office would enable him to make something in 
addition by private tuition. 

1 See Favaro's "Galileo e Suor Maria Celeste," Florence, 1891, 
p. 25. 



No sooner was Galileo settled in his new office 
than he resumed, and with increased diligence, his 
physico-mathematical researches. In the first year 
he carried to greater length his previous studies on 
the centre of gravity, and arrived at results which 
excited afresh the admiration of the Marquis del 
Monte ; he discovered that peculiar geometrical 
curve to which he gave the name cycloid, and 
attempted the problem of its quadrature ; 1 and all 
the while he was steadily revolving those novel ideas 
on motion, which were creeping into his mind, and 
which were to be the basis of his greatest and 
latest work. In pursuance of these ideas, he now 
began a systematic investigation (with experiment) 
of the mechanical doctrines of Aristotle. 

Galileo was not the first to call in question the 

1 The cycloid is the curve described by a point in a circle (as the 
nail in the rim of a carriage wheel) while it makes one revolution 
along a horizontal base. Soon after its discovery, and on Galileo's 
recommendation, it was applied in the formation of the arches of the 
bridge (Ponte di Mezzo) over the Arno in Pisa. Galileo guessed that 
the area contained between the cycloid and its base is three times that 
of the describing circle, but he was unable to demonstrate this geo- 
metrically a task which his disciple Torricelli achieved soon after his 


1589-1592] TEACHING 23 

authority of Aristotle in matters of science. It is 
now known that the celebrated painter, Leonardo 
da Vinci (1452-1519), held many views opposed 
to the Aristotelian philosophy, and even anticipated 
Galileo in some of his discoveries. But as da 
Vinci's scientific writings (mostly short notes and 
memoranda) remained in manuscript, practically 
lost to the world, till I797, 1 it is not likely that 
his views were known to any one. Also Nizzoli, 
Varchi, Benedetti, and others, had attacked in a 
general way, or in particulars, the peripatetic 

While, therefore, Galileo was not the first to 
question the authority of Aristotle, he was un- 
doubtedly the first whose questioning, as embodied 
in his acts and writings, produced an effect in 
men's minds which it would not be exaggerating 
to call a revolution. The reason is not far to seek. 
The spirit of free thought and free enquiry was 
asserting itself in every department. As in the 
reformation of religious doctrines, so in science, 
men were beginning to shake off the old supersti- 
tions. Galileo, in a word, came at the psycho- 
logical moment, and, above all, he came armed 
with a weapon of convincing force experiment. 
He was not content, like his precursors, with 
merely giving an opinion, supported or not by 
wordy metaphysical arguments, but what he 
asserted as well as what he denied he proved 
to ocular demonstration. 

The results of his researches the foundations 

1 When Venturi brought them to notice in his " Essai sur les 
Ouvrages Physico-Math&natiques de Leonard da Vinci," Paris, 1797. 


of dynamical science are given at great length in 
his treatise " De Motu Gravium," 1590, which, as 
was his custom then, and for many years after, was 
circulated in manuscript, and only appeared in print 
two hundred years after his death. 1 As most of 
these early theorems were afterwards developed and 
incorporated in his larger work, " Dialogues on Two 
New Sciences" (1638), we shall reserve our notice 
of them till we reach that period of his life. Here, 
then, we need only say, that as fast as he succeeded 
in demonstrating the falsehood of any of Aristotle's 
positions he did not hesitate to denounce them 
from his professorial chair, and perhaps with too 
much energy, at least for his own comfort, since 
the immediate result was to irritate more and more 
his colleagues of the academic body, who, as we 
have seen, were never too well disposed towards 

We must, however, say something here of his 
celebrated experiments on falling bodies, on account 
of their associations with the Leaning Tower of Pisa 
one of Italy's many curious monuments. Nearly 
two thousand years before, Aristotle had asserted 
that if two different weights of the same material 
were let fall from the same height, the heavier 
would reach the ground sooner than the lighter in 
the proportion of their weights. The experiment 
is certainly not a difficult one, but nobody thought 
of that method of argument, and consequently this 
assertion was received upon Aristotle's ipse dixit 
among the axioms of the science of motion. 

1 In Alberi's "Opere di Galileo Galilei," 16 vols,, Florence, 
1842-56; or better, Favaro's new edition, where they are given more 
accurately, and for the first time published completely. 


Galileo, however, now appealed from the authority 
of Aristotle to that of his own senses, and main- 
tained that, with the exception of an inconsiderable 
difference due to the disproportionate resistance of 
the air, they would fall in the same time. The 
Aristotelians ridiculed and refused to listen to such 
an idea. But Galileo was not to be repressed, and 
determined to make his adversaries see the fact 
as he saw it himself. So one morning, before the 
assembled University, professors, and students, he 
ascended the leaning tower, taking with him a 
lo-lb. shot and a i-lb. shot. He balanced them 
on the over-hanging edge and let them go to- 
gether. Together they fell, and together they 
struck the ground. 

Neglecting the resistance of the air, i.e. suppos- 
ing the bodies to fall in a vacuum, Galileo 
had found them to be subject to the following 
laws : 

1. All bodies fall from the same height in equal 

2. In falling the final velocities are proportional 
to the times. 

3. The spaces fallen through are proportional to 
the squares of the times. 

The correctness of the first law was easily 
established by the leaning tower experiments, and 
the better to prove the others he devised the 
inclined plane a long straight piece of wood, along 
which a groove was accurately made, and down 
which a bronze ball was free to move with the least 
friction. With this he proved that, no matter what 
the inclination of the plane was, and, consequently, 

26 PROFESSOR IN PISA [ I5 8 9 - 

no matter what the time was, the movement of the 
ball was always in accordance with the laws. 1 

It might have been thought that such experi- 
ments as these would have settled the question de- 
cisively. Aristotle, the master, would certainly have 
accepted them in disproof of his own dogma, but 
his disciples were embued with no such frankness, 
and would not be convinced. With the sound 
of the simultaneously fallen weights ringing in 
their ears, they still persisted in maintaining that 
a weight of 10 Ibs. would reach the ground in a 
tenth of the time taken by one of I lb. ? because they 
were able to quote chapter and verse in which 
Aristotle assured them that such is the fact ! 

A temper of mind like this could not fail to 
produce ill-will towards one who felt no scruples in 
exposing such folly. With the exception of the new 
Professor of Philosophy, Jacopo Mazzoni, the whole 
body of the teaching staff, as well as the heads of 
the University, now turned against our young 

For some time these feelings of animosity had 
no serious effects, but, no doubt, Galileo was " boy- 
cotted" and subjected to many petty annoyances. 
Soon, however, a wholly unforeseen circumstance 
came to the aid of the Aristotelians, and led to 
Galileo's retirement from Pisa. Giovanni de Medici, 
the natural son of Cosimo I., was at the time 
Governor of Leghorn. He had a bent for 
mechanics, and was not unskilled as an engineer 

1 Naturally these experiments would show the necessity of some 
accurate measurer of time, and so we are not surprised to learn that 
Galileo again occupied himself with the pendulum as such a measurer. 
See Favaro's " Galileo e Suor Maria Celeste," p. 32. 


and architect. Amongst other contrivances, he had 
just designed a monster dredging machine, which 
he wished to employ in clearing the harbour of 
Leghorn. A model was submitted to the Grand 
Duke, by whom Galileo was commissioned to 
examine and report upon it. He did so, and 
declared it to be useless, an opinion which sub- 
sequent experiment (with an actual machine) fully 
confirmed. That the discomfited inventor should 
be mortified at this failure is natural ; but that he 
should for no other reason be angry with Galileo, 
and should seek to injure him, is not so intelli- 
gible. However, so it is stated, and the young 
prince was easily induced to join hands with the 
Aristotelians in an onslaught on their common 
aversion. Hisses were now heard at his lectures ; 
cabals were started at Court; and, altogether, the 
position speedily became so intolerable that 
Galileo resigned his post, before the three years' 
term had expired, and once more returned to 
Florence. This was about the middle of 1592. 

Other circumstances of an economical character, 
no doubt, contributed to this decision. We have 
seen that out of his salary of ^13 per annum he 
was expected to contribute (and did so willingly) 
to the support of the family ; but miserable as the 
stipend was, he seldom received the whole of it. It 
was the custom in Pisa to put the professors under 
stoppages for all lectures not given, and at the end 
of the scholastic year they were, as a rule, called 
upon to refund a sum corresponding to the number 
of lectures missed, and proportional to the salary. 
Now, owing to an inundation of the Arno, Galileo 


was unable to take up his post on the opening day 
of the session ; and on another occasion, while in 
Florence on some urgent business, a sudden illness 
of his mother detained him some days over the 
specified time, yet, although he wrote to the head 
of the University explaining the causes of his deten- 
tion in each case, the rule was rigorously enforced 
in the first year to the extent of one-tenth of 
his salary ! l 

Indeed, his retirement from Pisa was no new 
or sudden resolution. He had not been many 
months there, when the ever-pressing money 
difficulty, and the undisguised antipathy of his 
colleagues, made him think of throwing up the 
post. Thus, it appears from his correspondence 
with the Marquis del Monte that early in 1590 he 
sought his friend's aid in obtaining the Mathe- 
matical Chair of Padua, which was vacant since 
January 1588 by the death of Moletti; but at this 
time as well as later (early in 1592) his efforts were 
not successful. 

To this period belong most of Galileo's literary 
productions. His "Capitolo in Biasimo della 
Toga," written in 1590, is a fragment of a play, an 
amusing though somewhat licentious burlesque, in 
which he ridicules the University ordinance com- 
pelling the professors to wear the gown, not only 

1 To eke out his pittance Galileo had to give up much of his time 
to the drudgery of private lessons. On the strength of a letter to his 
father, dated I5th November 1590, and asking fora copy of the works 
of Galen, some of his biographers conclude that he was then practising 
as a physician, or reading with medical students ; but it is more 
likely, as Professor Favaro says, that " Galen was wanted, not for the 
purpose of coaching, but for the many anti-Aristotelian arguments 
which the work contains " (" Galileo e Suor Maria Celeste," p. 26,) 


when actually engaged in lecturing, but when 
passing through the streets and visiting their 
friends. This was another cause of offence to the 
academic body, and the author was set down as 
a man of easy morals, and little mindful of the 
professorial dignity. 

About the same time Tasso's "Jerusalem 
Delivered" was being hotly criticised at the 
Accademia della Crusca of Florence. This cele- 
brated academy, the first of its kind, and still 
flourishing, was founded 1582 by Cosimo I., Grand 
Duke of Tuscany, to maintain the purity of the 
Italian language, or, as the name (Crusca = bran) 
imports, to sift the flour from the bran. In the 
exercise of this praiseworthy object the academy 
often gave offence by condemning all works which 
did not conform to its rules, and among the works 
thus censured was the "Jerusalem Delivered " of 
Torquato Tasso. Galileo must be held to have 
contributed to this result by his very severe 
critique on the style, construction, and characters 
of the poem. He is said to have known by heart 
the " Orlando Furioso" of Ariosto, whom he called 
the divine, but, according to all competent critics, 
his appreciation of the one is as excessive as his 
disparagement of the other. 1 The following 
sentences will give an idea of this too scathing 
production : "I am sometimes aghast at the 
foolish things this poet sets himself to describe." 
"To my mind this poet is poor and miserable 

1 His copy of the "Orlando Furioso" has been preserved. It is 
full of notes and corrections which critics say are just and ingenious. 
See " Postille air Ariosto " in Alberi's vol. xv., or Favaro's vol. ix. 


beyond all expression, whereas Ariosto is rich, 

magnificent, admirable." " Eh, Signor Tasso, 

you understand nothing of your art, you besmear 

much paper and only make in the end pap for 

cats." In later life Galileo considerably modified 

his views, but still could only relish Tasso after 

Ariosto " as one relishes cucumbers after melons." l 

Besides these effusions, Galileo has left us 

the outline of a comedy in prose, for writing 

which some of his biographers blame him much, 

and still more for preserving it; also a number 

of sonnets, some of which are of doubtful 

authenticity, and ought, perhaps, to be credited 

to his son Vincenzio, a MS. volume of whose 

verses, dated 1637, is now in the Riccardian 

Library, Florence. Amongst his friends in later 

life was Antonio Malatesti, the poet and friend 

of Milton, to whom a copy of his " Sphinx," or 

poetical enigmas, was presented. This curious and 

somewhat irreverent work has prefixed a number 

of commendatory verses, amongst which is a sonnet 

by Galileo on the telescope, which he presented to 

the Grand Duke. 2 This and three other sonnets 

have been printed in Alb&ri's edition, 1842-56, since 

1 See his letters of 5th November 1639, and iQth May 1640, both 
addressed to his friend, Francesco Rinuccini. At the time Tasso was 
under restraint in a kind of maison de sant^ and this controversy with 
the della Cruscans grievously wounded him. But in the end it tended 
more to spread the knowledge, and with that knowledge the fame, 
of his " Gerusalemme Liberata," than permanently to injure it. For 
a long time it was thought that Galileo's essay, " Considerazioni al 
Tasso," had perished, till the Abbe Serassi discovered a MS. copy 
about 1780, whilst collecting materials for his "Life of Tasso," 
published in Rome in 1785. 

a u Notes and Queries" (1853), vol. viii. p. 295, where the verses 
are given. 


which Professor Favaro has collected three others, 
and a longer piece which, from internal evidence, he 
assigns to the period of Galileo's professorship in 
Pisa, 1590-92. This we venture to reproduce as 
a fair specimen of our philosopher's versification 
recently brought to light. 

" Oh poveri Dottor mal arrivati ! 

Voi siete stati pure i bei minchioni 
A dare agli scolar tanti capponi, 
Con rischio d'esser tutti condennati. 

" Qui non si guarda che sien mandati 
Editti, Bandi, Prescrizioni j 
Qui non val nulla Monsignor Capponi 
Per dio, n'avete ad esser gastigati. 

" Venite qua ; non e una vergogna, 
Un vituperio espresso, una pazzia, 
Un obbrobrio da mitera e da gogna, 

" Avere i polli in casa, e darli via 

Senza ragione e quando non bisogna, 
A chi viene a can tar la Befania ? 

" E poi a una genia 
Che per saziar loro ingordigia Jhterna 
Avrian data la stretta a vita eterna ? 

" In questa lor Taverna, 
Cioe congrega di gran Tavernieri, 
Hanno condotto un Conte, ed un Alfieri, 

" Che son due masnadieri, 
Ch& Tun de 1 ghiotti & Re, Taltro e Monarca : 
Guai a colui che con costor s'imbarca ! 

" S' egli entravan neir Area, 
Dove campb No& co' suoi parenti, 
E con tutte le razze de' viventi, 

"Non crediate altrimenti 
Che le spezie si fusser propagate, 
Che si poteva dir, le son sonate ; 

32 PROFESSOR IN PISA [i S 8 9 - 

" Perch& queste brigate 
Non pur mangiavan le starne e gli storni, 
Le pecore, le capre e i liocorni, 

" Ma in que' quaranta giorni 
Asini e buoi morivan tutti quanti, 
Orsi, draghi, serpenti e liofanti. 

" Hanvi poi tanti e tanti 
Cavalier da far prove memorande 
Intorno ai piatti, intorno alle vivande, 

" Che sarla cosa grande 
Dir del Mannelli 1'ingordigia orrenda, 
del Sertin da quella gran faccenda 

" Dir la furia tremenda, 
Un rasciugar di piatti, e d'altri vasi 
Dell' Ansaldi, del Medici e del Masi, 

" Hannovi anco quel Rasi ; 
Di questo non occorre far paroia, 
Perche ognun sa ch' ei tira ben di gola. 

" Or da costor m'invola 
Con quel bocchino, e coi leggiadri sguardi 
Quel tristo Trafuriel di Carlin Bardi. 

" Che venne al quant o tardi, 
Essendo stato fino alle tre ore 
Non so dal Confessoro o dal Dottore ; 

"E vigiuro di cuore 
Che mi parea con quello spadaccino 
Qualche San Giorgio, o quaiche San Martino. 

" Evvi anco un Lupicino, 
Che divora, trangugia, anzi tracanna ; 
II nome solamente lo condanna." 

Early in 1591, Virginia, the eldest of Galileo's 
sisters, was married to Benedetto Landucci, son 
of the Tuscan ambassador at Rome during the 
pontificate of Leo X. Writing to his father on 
26th December 1590, this most loving of brothers 
says : 


11 1 am preparing for Virginia a set of silken bed- 
curtains, the silk for which I bought at Lucca, and 
have had it woven at little cost, so that, although 
the stuff is one and a quarter yards wide, it only 
cost me about three carlini the yard. The stuff is 
made with selvage, and will be sure to please. I am 
now having made the silk fringes for ornamenting 
the curtains, and could also have the bedstead made 
if desired. I beg you not to speak of this in the 
house, as I wish it to be an unexpected surprise. I 
will bring them at the Carnival holidays, and, if you 
wish, I could also bring enough to make four or five 
vests of damask and velvet of an exquisite design." 

Not content with this present, which, considering 
his scanty means, was more than liberal, he further 
bound himself in the marriage contract to provide a 
dot, the non-payment of which, as we shall see, 
brought on him no end of sordid annoyances his 
ungracious brother-in-law going so far as to threaten 
him with prison. 

On his return to Florence (middle of 1592) 
Galileo's position was truly pitiable. Without 
employment, and with no immediate prospect of 
obtaining it, the monetary situation must have 
appeared to him overwhelming, aggravated as it 
was by the death of his father on 2nd July 1591. 
Besides his mother, there was a brother, Michel- 
angelo, who had received a good musical educa- 
tion from his father, but who had not yet been 
able to contribute anything towards the household 
expenses; and two sisters, Livia and Elena all 
entirely, or almost entirely, depending on him 
for their daily wants. 



IN our second chapter we saw that Galileo long had 
designs on the Mathematical Chair in Padua, which 
had been vacant since January 1588, another fact 
which shows the little value that was attached to 
pure science even in learned Padua. 1 Now he again 
approached his friend, the Marquis del Monte, on 
the subject Del Monte was a distinguished pupil of 
the Padua University, had many friends there, and 
also a relative who was high-placed in the military 
service of the Venetian republic. With letters of 
introduction from this influential man, Galileo set 
out for Venice towards the end of the summer of 
1592, all his worldly goods (as he used afterwards to 
tell his friends) being contained in a trunk which 
did not weigh loolbs. He passed through Pesaro, 
the home of his noble friend and patron, and halted 
at Padua, where he was warmly received by 
Gianvincenzio Pinelli, a learned man of Genoese 
extraction long domiciled at Padua, and an intimate 
friend of del Monte. Armed, further, with recom- 
mendations from Pinelli, Galileo arrived in Venice 

1 See remarks on this subject, p. 10 ante, 

i592-i6io] PROFESSOR IN PADUA 35 

about ist September, and was met with the alarming 
intelligence that a formidable rival was already in 
the field, namely, Giovanni Magini, whom we have 
before mentioned as the Professor of Mathematics in 
Bologna, whose term there was about to expire, and 
who was long known to have aspired to the Chair at 
Padua. However, with the aid of his friends, del 
Monte and Pinelli, and of their friends in Venice, 
Galileo had the good fortune to be selected. Being 
informed privately of this happy issue, he set out on 
2Oth September for Padua, en route for Florence, to 
wind up his affairs there, and to obtain the permis- 
sion of his sovereign to withdraw from Tuscany. 

On 26th September he was gazetted, and as 
the terms of the diploma (preserved amongst the 
Galilean MSS. in the National Library, Florence) 
will serve to show the estimation in which our 
philosopher was held, we reproduce it here. 

(After preamble.) "Owing to the death of 
Signor Moletti, who formerly lectured on Mathe- 
matics at Padua, the Chair has been for a long time 
vacant, and, being a most important one, it was 
thought proper to defer electing any one to fill it till 
such time as a fit and capable candidate should 
appear. Now there has been found Domino Galileo 
Galilei, who lectured at Pisa with very great honour 
and success, and who may be styled the first in his 
profession, and who, being ready to come at once 
to our said University, and there to give the said 
lectures, it is proper to accept him. Therefore, the 
said Domino Galileo Galilei is hereby appointed 
Mathematical Lecturer in our University for four 
years certain, and two uncertain (and the last two 
are to be at the will and pleasure of our Serenity), 
with the yearly salary of 180 florins." 


The gaining of this coveted post over so formid- 
able a rival as Magini was, of course, very gratifying 
to the amour propre of Galileo, but it was also very 
welcome from the money point of view. The salary 
was exceptionally good for the time/ and, owing to 
the large number of students who flocked to Padua, 
he would be able to add considerably to his income 
by private lessons. 

The Paduan session opened on ist November, 
but, unlike his treatment at Pisa, our new professor 
was allowed ample time to settle his affairs in 
Florence, and to prepare his inaugural address, 
which was to be worthy alike of the occasion and 
the man. Accordingly, on 7th December 1592, 
Galileo entered on his new duties with a discourse 
which is said to have won the greatest admira- 
tion, not only for its profound knowledge, but for 
its eloquence and elegance of diction. It is thus 
referred to, and evidently by one who heard 
it, in Tycho Brahms "Astronomiae Instauratae 
Mechanica," 1598. 

" Interea, Gallilaeus de Gallilaeis Florentinus 
Professionem Mathematicam hie adeptus est, qui 
suarum lectionum septimo Decembris initium fecit. 
Exordium erat splendidum in magna auditorum 
frequentia. Datae Patavii 28 Decembris, Anni 

For some time after his arrival at Padua, Galileo 
was apparently the guest of Pinelli, whose library of, 
it is said, 80,000 volumes would be useful in prepar- 

1 It was still very much under the salaries attached to the other 
chairs. Thus, the Professors of Philosophy and of Civil Law received 
annual stipends of 1400 and 1680 florins respectively, 

i6io] TREATISES 37 

ing his inaugural address. He then appears to 
have established himself in a modest house in the 
vicinity of the Church of San Giustina, on the Prato 
della Valle (now Piazza Vittorio Emmanuele). 
Little did he then think as he strolled about the 
Prato, then a Grande Place for f&tes and spectacles 
of all kinds, that his statue would be one of seventy- 
seven which would be erected in years long after 
to commemorate great men who had made Padua 
illustrious for all time. 

During the first few years at Padua, Galileo 
displayed an extraordinary and versatile activity. 
He wrote a number of treatises, chiefly for the use 
of his pupils, among the larger of which may be 
mentioned : On Military Architecture, on Fortifica- 
tions, on Mechanics, on the Sphere, on Accelerated 
Motion, on Gnomonics. All of these attained a 
wide circulation in manuscript copies ; some were 
not printed until long afterwards, while others, like 
the paper on Gnomonics, are unfortunately lost. 
Others, again, strayed beyond the pupils and 
friends for whom they were intended, and found 
their way into the hands of persons who did not 
scruple to claim and publish them as their own. 

Galileo's treatise on Mechanics (" Delia Scienza 
Meccanica"), written in 1594, deals with the powers 
of the lever, pulley, and screw, and concludes with 
an account of the Archimedian Screw for raising 
water, followed by a short fragment " On the Force 
of Percussion." 

In the introductory remarks Galileo demonstrates 
the important principle of Virtual Velocities, which, 
according to Professor Jack, marks, with his laws of 


falling bodies, the greatest advance in mechanical 
science since the world began. Here, perhaps, it 
will be best described in the popular language of 
Professor Jack : 

" It was in connection with his investigations 
of motion on a plane that Galileo laid down the 
principle that, perhaps, serves best as the basis of 
the theory of balancing forces, the principle of what 
is called Virtual Velocities. Every one is familiar 
with it, in the ordinary maxim, that what is gained 
in speed is lost in power. In the board laid across 
a fallen tree, on which children see-saw, the lighter 
child is put at the extremity of the longer arm. 
With a plank 12 feet long, a child 50 Ibs. weight 
will be balanced against one 70 Ibs. weight when 
the plank rests on the tree 7 feet from the light 
child's end, and 5 feet from the heavy one's. When 
they swing the amount of swing is proportional to 
the distances from the fixed point. If the plank 
moves, so that the child at the 7 feet end rises 
through 7 inches, the other goes down through 5. 
In every case like this, where forces are in equi- 
librium on a system, we can imagine a motion given, 
every point moving according to the geometrical 
circumstances. Let us imagine such a motion. 
When two forces act on a system and keep it at 
rest, multiply the space through which the point of 
application of each force moves, referred to the line 
in which the force acts, by the measure of the force. 
When there is equilibrium the resulting quantities 
are equal and of opposite signs. The one child 
weighing 50 Ibs, rises vertically through 7 inches, 
and we may call the product 350 inch-lbs. upwards. 
The 70 Ibs. child moves in the same time 5 inches 
downwards, and the product, which is 350 inch-lbs. 
downwards, is equal and opposite to the other. If 
there is equilibrium it must always be so ; if it is so 


there must be equilibrium. It is to Galileo that 
we owe this most fruitful of statical principles. It 
can easily be extended to the case when any number 
of forces act at any number of points on a body or a 
system ; but it was not till a century later that John 
Bernouilli could state it in all its generality, or show 
how admirably it serves as a sufficient basis for the 
whole theory of equilibrium. 3 ' 1 

The treatise on the Sphere, which was first 
published at Rome in 1656 (fourteen years after 
Galileo's death), is supposed by some authors to be 
apocryphal, as it teaches the Ptolemaic cosmogony, 
placing the earth immovable in the centre, and 
adducing the usual arguments. But this does not 
make the work necessarily apocryphal, for we have 
it under his own hand that for some years he taught 
the Ptolemaic system in his classes out of compliance 
with popular feeling, although at heart he was a 
follower of Copernicus. 2 

In his first letter to Kepler, dated 4th August 
1597, and acknowledging the receipt of the latter 's 
" Mysterium Cosmographicum," he says : 

" I have as yet read nothing beyond the 
preface of your book, from which, however, I 
catch a glimpse of your meaning, and feel great 
joy on meeting with so powerful an associate 
in the pursuit of truth, and, consequently, such 
a friend to truth itself; for it is deplorable that 
there should be so few who care about truth, 
and who do not persist in their perverse mode 
of philosophising. But as this is not the fit 
time for lamenting the melancholy condition of 

1 " Nature" (1879), vol. xxi. p. 40. 

a Maestlin, Kepler's master, did the same, while all the time he 
was well known to be a Copernican. 


our times, but for congratulating you on your 
elegant discoveries in confirmation of the truth, 
I shall only add a promise to peruse your book 
dispassionately, and with the conviction that I 
shall find in it much to admire. 

"This I shall do the more willingly because 
many years ago I became a convert to the 
opinions of Copernicus, 1 and by his theory have 
succeeded in explaining many phenomena which 
on the contrary hypothesis are altogether in- 
explicable. I have arranged many arguments 
and confutations of the opposite opinions, which, 
however, I have not yet dared to publish, 
fearing the fate of our master, Copernicus, who, 
although he has earned immortal fame among a 
few, yet by an infinite number (for so only can 
the number of fools be measured) is hissed 
and derided. If there were many such as you 
I would venture to publish my speculations, but 
since that is not so I shall take time to consider 
of it" 2 

In the early summer of 1593 Galileo con- 
tracted an illness, which nearly proved fatal, 
and from which he suffered at intervals all 
through life. A party of three young men (so 
Viviani tells the story), of whom Galileo was 
one, "were enjoying at an open window in the 
country a current of air which was artificially 
cooled by a fall of water. They, unfortunately, 

1 See also the "Dialogues on the Two Systems of the World," 
second "Day," where Sagredo tells how he was led in early 
life to adopt the Copernican doctrine, and where Galileo evidently 
describes his own mental evolution. 

a This interesting letter was the beginning of the friendship 
of these two great men, which lasted uninterruptedly till 1630, the 
date of Kepler's death. There is a still earlier admission in his 
letter of soth May 1597, to his friend Professor Mawoni of Pisa. 


fell asleep under its influence, and so great was 
its effect on Galileo's hitherto robust constitution 
that a severe chronic disorder ensued, which 
showed itself in acute pains in the body, 
accompanied by frequent haemorrhages and loss 
of appetite and sleep. The others suffered still 
more severely, for one died in a few days, while 
the third became deaf and died in a short time 

Professor Favaro has been at great pains to 
corroborate this strange story, and has suc- 
ceeded in giving it a more matter-of-fact appear- 
ance. He has identified the place as the Villa 
in Costozza, which is not far from Vicenza, and 
which then belonged to the Count da Trento. 
The Villa still exists, and in one of the rooms 
on the first floor he found an opening to a 
narrow passage or tunnel which led to a 
neighbouring cavern. The air issuing from this 
cavern is always cool (Favaro found it to be 
52 Fahr.), and, perhaps, sometimes poisonous, 
like the Grotto del Cane, near Naples, so 
celebrated for its mephitic vapours. . This would 
explain the disastrous results of sle'eping under 
its influence which befell Galileo and his 
companions. 1 

While carrying on his professorial duties, 
giving private lessons, and writing learned tracts, 
Galileo was occupying himself profitably in other 
ways. Thus it would appear that his skill as 
an engineer was often in request by the State, 
for which he is said to have designed, or super- 
1 Favaro's "Galileo e Suor Maria Celeste," pp. 49-53. 


intended the construction of, various works and 
machines. 1 Amongst the latter may here 
be noted a machine for raising water, of small 
dimensions but of great power, so that one 
horse could raise the water and distribute it 
through twenty channels. For this the Venetian 
republic gave him the exclusive use for twenty 
years, under a patent dated i5th September 
1594; but, although it was tried with success 
in the garden of the Contarini Palace in Venice, 
it never came into much use. 

About 1596-7 he invented a more profitable 
instrument, his Geometrical and Military Compass. 
This useful instrument is now called the Sector, 
and is to be found in most cases of mathematical 
instruments. It consists of two straight rulers 
connected by a joint so that they can be set to 
any required angle. On one face are four pairs 
of lines. 

Arithmetical lines, which serve for the division 
of lines, the solution of the Rule of Three, the 
equalisation of money, the calculation of interest. 

Geometrical lines, for reducing proportionally 
superficial figures, extracting the square root, 
regulating the front and flank formations of 
armies, and finding the mean proportional. 

Stereometrical lines, for the proportional reduc- 
tion of similar solids, the extraction of the cube 
root, the finding of two mean proportionals, and for 
the transformation of a parallelepiped into a cube. 

1 So say Viviani and Gherardini in their biographies of Galileo, but 
Professor Favaro, after a diligent search among the archives of Venice, 
could find nothing to bear out the statement For this and other 
cogent reasons he doubts its accuracy. 


Metallic lines, for finding the proportional 
weights of metals, and other substances, for trans- 
forming a given body into one of another material 
and of a given weight. 

On the other side of the instrument are : 

Polygraphic* lines, for describing regular 
polygons, and dividing the circumference into 
equal parts. 

Tetragonical lines, for squaring the circle or 
any other regular figure, for reducing several 
regular figures to one figure, and for transforming 
an irregular rectilineal figure into a regular one. 

Joined lines, used in the squaring of the various 
portions of the circle and of other figures contained 
by parts of the circumference, or by straight and 
curved lines together. 

There is joined to the compass a quadrant, 
which, besides the usual divisions of the astro- 
nomical compass, has engraved on it a squadron 
of bombardiers, and, in addition, transversal lines, 
used for taking the inclination of a scarp of a wall. 

From the encouraging reception given to this 
invention, orders for which came from all parts 
of Europe, Galileo determined to open a work- 
shop in his own house, no doubt in order that 
the manufacture of this and other scientific 
apparatus 1 might proceed uninterruptedly under 
his personal supervision, and so be less liable to 
piracy. This we gather from an entry in his 
Day-book under 5th July 1599. 

1 His papers show that large numbers of the Geometrical and 
Military Compass, in copper and silver, were manufactured, and that 
he was also making magnetic compasses, and various kinds of 
drawing instruments. 


" Messer Marcantonio Mazzoleni, mechanician, 
comes to reside in my house to work for me, 
and at my cost, on mathematical instruments, I 
undertaking to bear the expenses of him, his 
wife, and child, and to pay him in addition the 
sum of six ducats per annum." 

This is one of the instances, before referred to, 
where Galileo's manuscripts and ideas got into the 
hands of people who were not ashamed to publish 
them as their own, and to denounce the author 
as an impudent plagiarist. Some years after the 
invention, finding that his right to it was being 
disputed, Galileo published a description of it and 
dedicated the book to his pupil, Prince Cosimo, 
son of the Grand Duke of Tuscany. 1 This was 
speedily followed by another book, the production 
of Baldassare Capra, a young Milanese, in which 
he claimed the invention as his own, and accused 
Galileo of piracy. 2 The matter was brought before 
the University authorities, and Galileo was able 
to show that he had made the invention as early 
as 1597, and had explained its construction and 
uses to numerous persons in Padua and elsewhere, 
amongst them being Capra himself! These state- 
ments were supported by depositions of well- 
known men, as Gio. Fran. Sagredo, Giacomo 
Badovere, Mazzoleni (Galileo's mechanician), 
Giacomo Alvise Carnaro, and Fra Paolo Sarpi. 

1 " Operazioni del Compasso Geometrico e Militate." The dedica- 
tion is dated Padua, loth July 1606. This is his first printed work. 

2 This work is entitled "Usus et Fabrica Circini Cujusdam 
Proportions, " Padua, March 1607. A modern writer speaks of 
Capra as "one of those parasites who live at the expense of the 
talent and the renown of others." Chasles : " Galileo, sa Vie et son 
Proces," Paris, 1862, p. 20. 


The last-mentioned only need be quoted. Writing 
from Venice under date 2oth April 1607, he 
affirms and attests that he had carefully compared 
the two works in dispute, and had found Capra's 
to be little more than a Latin translation of 
Galileo's Italian. He then goes on : 

" I further affirm that about ten years ago In 
Padua Signor Galileo showed me the instrument 
(described in his book) and explained its uses ; 
and that about two years later, the said Signor 
made me a present of one, which I still have in 
my possession." 

As Capra made no defence, the University 
authorities did not take long to decide. Under 
date 4th May 1607, they unanimously decreed 
that his book was a scandalous plagiary and an 
insult to Galileo and the University (of which 
Capra was a member) ; that all the copies in 
the possession of the author and his publisher, to 
the number of 483, be given up to them for sup- 
pression " in the way that seems best " ; and that 
proceedings be taken against the printer and 

Galileo afterwards published a full account of 
this affair in his " Difesa contro alle Calunnie ed 
Imposture di Baldassare Capra." The first part 
is taken up with a defence of his views on the 
new star of 1604, which Capra had attacked in 
another publication moved thereto, as Viviani 
says, " by envy of the universal applause which 
accrued to Galileo from his lectures on the 

From the opening passages of Galileo's "II 


Saggiatore " (1623), it would appear that the real 
author of the book which went under Capra's 
name was Simon Mayer, a German graduate of 
Padua, whom we shall meet with later on arro- 
gating to himself the merit of two of Galileo's 
astronomical discoveries. On this occasion, as 
soon as he found our philosopher intent on 
resenting the injury, he hastily quitted Italy, 
leaving his friend Capra to bear alone the shame 
of the exposure which followed. 

In September 1598, the first period of Galileo's 
appointment expired, which the Venetian Senate 
were in no hurry to renew formally ; not because 
of any doubt as to the incumbent's fitness, but 
because of the dreaded increase of salary which 
was usually expected on re-appointment, and which 
all governments like to evade if they can. Galileo 
himself had allowed the first term to expire, and 
had nearly completed one year of the second, 
before taking any steps in the matter. Then, 
about the middle of 1599, with the advice and 
assistance of Pinelli, Gianfrancesco Sagredo, a 
young Venetian of great promise, and other 
friends, he formally requested that his appoint- 
ment be renewed, on an increased salary, as a 
precedent for which he cited the case of Professor 
Magini at Bologna, who on re-appointment was 
awarded a salary much in excess of that enjoyed 
by Galileo at Padua. 

The question of augmentation was apparently 
long and stoutly opposed on one side, and as 
hotly pressed on the other. The Doge, Contarini, 
complained that he was pestered on the subject, 


not only by Galileo's friends, but by his own 
household. " If Galileo, 31 he cried, " is not con- 
tent with his salary he can resign." Moletti, he 
pointed out, had never more than 300 florins, and 
it was an understood thing that the Professors 
should eke out their incomes by private lessons. 
In the end the appointment was renewed, on 
28th October 1599, for a further period of six 
years, commencing 27th September 1598. The 
salary was fixed at 320 florins (about ^70), and 
Sagredo was grumblingly bidden to warn his 
friend not to expect any further augmentation, 
" as the Senate did not choose to make his case 
a precedent for every learned and hungry foreigner 
who might think fit to press a similar claim." 

Galileo's reputation as a teacher was now 
widely spread over Europe, and numbers of 
young foreigners flocked to Padua to attend his 
lectures. Amongst these are noted the Arch- 
duke Ferdinand, afterwards Emperor of Germany ; 
the Landgrave of Hesse ; the Princes of Alsace 
and Mantua ; and a Prince Gustavus of Sweden, 
often confounded with the great Gustavus 
Adolphus. Our own William Harvey, the dis- 
coverer of the circulation of the blood, was a 
student at Padua, 1598-1602, and would no doubt 
be a frequent attendant. 

It is not certain when he moved from his 
modest house near the Church of San Giustina; 
but towards the end of 1 599 we find him installed 
in a large house in the Via Vignali, now Via 
Galileo. Here he was able to accommodate 
suitably his private pupils, of whom he now 


had large numbers resident with him, both Italians 
and foreigners. His private papers show that he 
looked after the catering himself, which must 
have been no light matter, seeing that he often 
had as many as twenty boarders at a time, some 
of whom were accompanied by servants or 
followers of some kind. Inclined to be prodigal 
by nature, Galileo made nothing out of his 
pupils' keep, being content if their contributions 
covered the expenses of house-keeping. 

With the house went a garden, to which in 
1603 he added an adjoining piece of ground 
containing a large arbour and vine-trellises. The 
care of this garden, the flowers, the fruits, the 
vines, was his great delight. He saw to every- 
thing and did much himself in the way of weed- 
ing, pruning, tying. Indeed, all his life he was 
very fond of gardening, which he followed as 
much as an education as a recreation and dis- 
traction from severer studies. Here he took his 
pleasure, sometimes alone, revolving deep things 
in philosophy, but more often surrounded by 
groups of his friends, or pupils, whom he now 
sported with, now charmed with performances on 
the lute, which he touched with a master's hand 

" As sweet and musical 
As bright Apollo's lute, strung with his hair," 

now conversed, as they strolled along the arbour 
and under the spreading vines, on any subject 
that presented itself the germination of seeds, 
the nutrition and vegetation of plants, the making 
of wines, philosophising all the while "from 
grave to gay, from lively to severe." We can 


imagine how charming and instructive his con- 
versations were, for Galileo had the habit of 
allowing no natural phenomena, however trivial 
in appearance, to escape him, and he found the 
advantage of this in his lectures and writings, 
as it furnished him with a stock of homely 
illustrations to which the daily experience of his 
hearers and readers readily assented, and which 
he could show to be identical in principle with 
the matter in hand. Thus he could always 

" Tongues in trees, books in the running brooks, 
Sermons in stones, and good in everything." 

"We seem to see him now," says Favaro, 
writing within gunshot of the sacred garden, 
"under the trellis of vines cared by his own 
hands, surrounded by loving friends and pupils, 
and discoursing with them on divine philosophy ; 
or presiding at an evening meal in summer spread 
under the grateful shade of trees or arbour ; or 
playing the lute, as he was always ready to do 
in convivial meetings. Oh ! how the remem- 
brances of such evenings passed with Galileo in 
his pleasant garden under the vault of our splendid 
sky must have impressed themselves on the 
memories of the youth of Italy, France, England, 
and Germany, who came to Padua to listen to 
our great master." 1 

Among the crowd of noble and learned men, 
with whom at this period Galileo had cemented 
a friendship which was only to be severed by 
death, may be mentioned (besides Pinelli) Fra 
Paolo Sarpi of the Order of Servites, Theologian 

1 " Galileo e Suor Maria Celeste," p. 73. 


and Counsellor of the Venetian Republic, and 
afterwards known as the Machiavelli of Venice ; 
Fra Fulgenzio Micanzio, Sarpi's devoted friend 
and colleague ; Fabrizio d'Acquapendente, the 
famous surgeon of Padua, who has been called 
"the Columbus of the human body," and under 
whom our great Harvey studied ; Antonio de 
Medici ; General del Monte ; and young Gian- 
francesco Sagredo, who developed into "a witty 
and eccentric patrician, whose house at Venice 
resembled a Noah's ark, containing all manner of 
beasts.". Pinelli took an opportunity of his corre- 
spondence with Tycho Brah6 to recommend Galileo 
"as a man whose friendship would be worth while 
cultivating." Tycho addressed a letter to Galileo, 
under date 4th May 1600, but the acquaintance went 
no farther, and the great Dane died at Prague, 
1 3th October 1601. 

To the name of William Harvey, whom we 
have mentioned above as, probably, a friend of 
Galileo, we may now add the names of a few 
others of English and Scotch nationality, as, 
Robert Fludd, "The Father of the English 
Rosicrucians," who was studying in Padua circa 
1602 ; Messrs Moore and Willoughby, both of 
whom are mentioned by Coryat in his " Crudities," 
the one as a doctor of physic, and the other as 
a learned student in the University. Riqhard 
Willoughby was one of Galileo's resident pupils, 
and evidently did him credit, for amongst the 
thousands of armorial bearings, etc., of distin- 
guished members of the University which cover 
its walls, appears that of Willoughby ; and a still 


greater compliment was paid him by the Master 
in the presentation of a copy, with an autograph 
inscription, of the " Difesa contro. . . . Baldassare 
Capra." A little later, Galileo had two Scotch 
pupils who were among his most devoted friends. 
These were John Wodderborn (or Wedderburn), 
whom we shall meet with later on as his 
master's champion ; and Thomas Seggett, who 
was also a friend of Kepler, and in whose 
" Album Amicorum," now in the Vatican library, 
Galileo inscribed his name. 1 Their coats-of-arms 
and memorial tablets are also on the University 
walls. 2 

To this period (1602) may be referred Galileo's 
invention of the air thermometer. The date is 
uncertain, for while Viviani asserts that the instru- 
ment was designed during the first term of his 
Professorship at Padua (1592-98), other evidence, 
on- which Galileo rested his claim when contested 
some years later, will only carry us back to 
about 1602, Thus, Castelli, writing to Ferdinando 
Cesarini, 2Oth September 1638, says: 

" I remember an experiment which our Signer 
Galileo had shown me more than thirty-five years 
ago. He took a small glass bottle about the size 
of a hen's egg, the neck of which was two palms 

1 Under date 13th August 1599. Galileo's signature, followed by 
a few verses referring to the telescope and the discovery of Jupiter's 
moons, is also in Brinck's album (under year 1614), and, curiously 
enough, is next to that of Cardinal Bellarmine. The verses are given 
in "Notes and Queries," January 1858, p. 44. 

2 Professor Darwin gives the names of one hundred English and 
Scotch students to whom memorial tablets are erected. See his 
" Monuments to Cambridge Men at the University of Padua." 
(Cambridge Antiquarian Society Proceedings^ March 1894.) 



long (about 22 inches), and as narrow as 
a straw. Having well heated the bulb in his 
hand, he inserted its mouth in a vessel containing 
a little water, and, withdrawing the heat of his 
hand from the bulb, instantly the water rose in 
the neck more than a palm above its level in 
the vessel. It is thus that he constructed an 
instrument for measuring the degrees of heat 
and cold." 

From this it is plain that the instrument con- 
sisted merely of a glass tube ending in a bulb, 
the air in which, being partially 
expelled by heat, was replaced 
by water from a glass vessel into 
which the open end of the tube 
was plunged. The different de- 
grees of temperature would then 
be indicated by the expansion or 
contraction of the air which re- 
mained in the bulb ; so that the 
scale would be the reverse of 
that of the thermometer now in 
use, for the water would stand 
at the highest level in the coldest 

So long as the orifice of the 
tube remained open, this instrument could not be an 
efficient measurer of temperature, for it was impos- 
sible to distinguish the expansive and contractive 
effects of heat and cold from the effects of varying 
atmospheric pressure. It was, in truth, a baro- 
meter as well as thermometer, although Galileo 
apparently did not recognise its utility as such. 



Galileo's friend, Sagredo, was the first to divide 
the tube into 100 degrees in 1613. He also appears 
to have experimented with closed tubes from about 
1615 ; but it was not until many years after (1653) 
that the practice of hermetically closing the orifice 
after exhausting the air was introduced. The 
credit of this capital improvement is due to 
Leopoldo de Medici, brother of Ferdinando II., 
who adopted the plan of expelling the air by 
boiling the spirit and sealing the end of the 
tube whilst the contained liquid was in an ex- 
panded state, thus depriving the instrument of 
its barometrical character and making it a true 
thermometer. 1 

We have said above that Galileo's right to this 
invention was contested, as in the case of his 
geometrical and military compass, and in others to 
which we shall come later on. It was claimed for 
Porta, Santorio, and Paolo Sarpi, in Italy ; for 
Robert Fludd and Francis Bacon in England ; 
and for the Dutchman, Drebbel. But in disproof 
of these claims it will be enough to say that the 
first mention of the instrument by Porta occurs in 
1606, by Santorio in 1612, by Sarpi and Fludd in 
1617, by Bacon in 1620, and by Drebbel in 1621. 

In 1604 the attention of astronomers was 
attracted to a new star which suddenly appeared 
with great splendour in the constellation Serpen- 

1 About 1611-1612 Galileo substituted spirit of wine for water; 
and later still Ferdinando II., a former pupil of Galileo, employed 
coloured spirit of wine, and reduced the dimensions of the tube. 
Mercury was first used by Lana in 1670. The Fahrenheit scale was 
adopted in 1724, that of Reaumur in 1730, and the Centigrade scale 
by Celsius in 1742. 


tarius. Maestlin, who was one of the first to 
notice it, thus describes it : 

" How wonderful is this new star ! I am certain 
that I did not see it before 2gth September, nor 
indeed, on account of several cloudy nights, had I 
a good view till 6th October. Now that it is on 
the other side of the sun, instead of surpassing 
Jupiter as it did, and almost rivalling Venus, it 
scarcely equals the Cor Leonis, and hardly sur- 
passes Saturn. It continues, however, to shine 
with the same bright and strongly sparkling light, 
and changes colour almost every moment, now 
tawny, then yellow, presently purple, and red, and, 
when it has risen above the vapours, most frequently 

Galileo appears to have noticed the new star 
very soon after Maestlin, i.e. on roth October; 
and (whether by accident or design is not 
known) he chose for the subject of his ordinary 
lectures in the session then opening the theory 
of the planets. This afforded his auditors the 
wished-for opportunity of getting his views on 
the new phenomenon, the appearance of which 
had given rise to the most bewildering statements. 
Some said it was a light in the inferior regions 
of space "the elementary sphere," but they did 
not explain how it got there; others, that it was 
an old star hitherto unnoticed; others again, 
foqnding their opinion on abstruse teleological 
grounds, declared that new stars were created 
by God from time to time, and that this was 
one of them; while, to add to the confusion, 
the astrologers deduced from it the wildest 

i6io] NEW STAR OF 1604 55 

After carefully watching the star for some 
time (it lasted eighteen months), Galileo resolved 
to expound his views in three extra-ordinary 
lectures, which were delivered to the public in 
the great hall (Aula Magna) of the University 
early in January 1605. I n the opening sentences 
of the first lecture, which are the only parts 
preserved to us, he took occasion to rebuke his 
auditors for their general insensibility to the 
wonders of creation daily exposed to their view, 
in no way less admirable than the new prodigy, 
to hear an explanation of which they had hurried 
in crowds to his lecture room. As regards the 
star itself we know, from references in his other 
writings, 1 that he demonstrated that it was neither 
a meteor, nor yet a body existing from all time, 
and only now noticed, but a body which had 
recently appeared and would again vanish. 
Unlike his contemporaries, Tycho Brah and 
Kepler, who thought that new stars (and comets) 
were temporary conglomerations of a cosmical 
vapour filling space; or, as is now thought, the 
result of some catastrophe or collision whereby 
immense masses of incandescent gases are pro- 
duced, Galileo suggested that they might be 
products of terrestrial exhalations of extreme 
tenuity, at immense distances from the earth, 
and reflecting the jsun's rays an hypothesis which, 
as we shall see later on, he also applied to 
comets. From the absence of parallax he showed 
that the new star could not be, as the current 

1 "Difesa contro alle Calunnieed Imposture d Baldassare Capra,'' 
and " Postille al Libro d' Antonio Rocco." 


theory held, a mere meteor engendered in our 
atmosphere, and nearer to us than the moon, but 
that it must be situated among the most remote 
heavenly bodies. 

This was inconceivable to the Aristotelians, 
whose notions of a perfect and unchangeable 
heaven, subject neither to growth nor to decay, 
were quite at variance with the introduction of 
any such new body. It is hard to say whether 
Galileo's colleagues, bred in the old philosophy, 
were more annoyed at the appearance of the star, 
or at his calling attention to it so publicly and 
forcibly. Controversy was now unavoidable at 
Padua, as a few years before at Pisa, and Galileo 
did not shirk it. He boldly threw down the 
gauntlet in favour of the Copernican theory, and 
repudiated the old systems of Aristotle and Ptolemy, 
which up to that time he had taught in his classes. 

The Aristotelians put forth one of their best 
advocates, Antonio da Montepulciano, to confute 
Galileo's views, and the latter replied in the only 
way possible by ridicule. With the aid of some 
of his pupils he . wrote and printed an exquisite 
squib in the Paduan dialect, entitled, " Dialogo 
de Cecco di Ronchitti da Bruzene in Perpuosito 
del la Stella Nuova." 1 

In 1604, when the second term of Galileo's 
Professorship expired, he applied for its renewal 
with a further increase of salary ; but, as usual, the 
Venetian authorities were slow to move. At this 

1 Padua, 1605, edited by Girolamo Spinelli. Reprinted with a 
modern Italian version in Favaro's edition of Galileo's works, 
vol. ii. p. 307. 



time Vincenzio Gonzaga, the reigning- Duke of 
Mantua, was anxious to attach him to his court 
and person, and made some tempting overtures, 
but nothing came of them. However, while in 
Florence during the summer of 1605, Galileo took 
an opportunity of interesting his young pupil 
Cosimo, son of the Grand Duke, in his case ; and 
at length, and mainly through the influence of 
the Tuscan Ambassador at Venice (prompted by 
Cosimo), he was reappointed for a third term of 
six years, with an augmented salary of 520 florins 
(about ^115), by decree of 5th August 1606. 

His public lectures were at this time so thronged 
that the ordinary class-rooms, large as they were, 
were often insufficient to contain his audiences. His 
more popular lectures, as, for instance, those on the 
new star, were delivered in the Aula Magna, the 
great hall of the University, and capable of holding 
1000 persons. Even this, according to Drink water, 
was not large enough, for " on several occasions he 
was obliged to adjourn to the open air." 1 

The Cattedra (chair or lecture-desk) which then 
existed in the Aula Magna, and which Galileo has 
made historical, is now preserved as a sacred relic 
in the Stanze di Galileo in the University buildings. 
It is made of stout rough-planed planks, untrimmed 
and unpainted, and held together by nails. The 
Cattedra shown in attached drawing is a modern 
structure. Around the walls are hung thousands 
of coats of arms of professors and students of Padua 
who. became distinguished in after life. 

1 " Life of Galileo" (Library of Useful Knowledge), London, 1833, 
p. 1 6. 

58 PROFESSOR IN PADUA [1592-1610 

The bust on pedestal shown on the left of the 
drawing is that of Galileo, by the sculptor Ferrari. 
It was presented by the Archduke Maximilian of 
Austria (the ill-starred Emperor of Mexico), and 
bore on the pedestal an inscription to that effect. 
After the Austrians were driven out of Italy this 
inscription was effaced, and replaced by the present 



IN 1607 Galileo had been studying the " De 
Magnete" 1 of Dr William Gilbert of Colchester, 
a book which had for him always a great fascina- 
tion, and for two reasons firstly, its arguments 
traversed many of the principles of the Aristotelian 
School ; and secondly, it contained a number of 
original experiments in electricity and magnetism, 
coupled with philosophical reflections of a far-reaching 
kind, which appealed to his own daring spirit. 

Up to Gilbert's time little was known of 
magnetism. The attractive power of the load- 
stone was known to Aristotle and Pliny, and the 
latter appears to have been also acquainted with 
its power to communicate this attractive property 
to other bodies. 

The polarity of the magnet, that is, its power 
of taking up a north and south direction when 
freely suspended, was known to the Chinese from 
a very early period. Thus, in the second century 
B.C., we find allusions to "magnetic cars" with 

1 " Physiologia Nova de Magnete, Magnetic! sque Corporibus," 
London, 1600. From a letter of Fra Paolo Sarpi, dated nth 
September 1602, it would appear that Galileo in that year first became 
acquainted with Gilbert's book. 



which ambassadors from distant countries were 
provided, in order that they should not miss the 
way on their return home. In the fourth century 
of our era Chinese captains employed the magnet 
to direct their courses across the open seas ; and 
it was through these that the knowledge of the 
compass was carried to India, and thence to the 
eastern shores of Arabia and Africa. The Arabic 
designations Zoron and Aphron (south and north), 
which Vincent de Beauvais 1 gives to the ends of 
the magnetic needle, indicate, like many Arabic 
names of stars which we still employ, the source 
whence Western nations received the elements of 
their scientific knowledge. 

The application of the compass to navigation, 
doubtless, soon led to the discovery of another 
property of the magnet, its declination or variation 
from the north pole, according to locality. It must 
have been known to the Chinese in' the twelfth 
century, as it is mentioned by a Chinese philosopher 
who wrote about the year mi. And Columbus 
made the same discovery on his first voyage to 
America in September 1492, 

The inclination or dip of the needle was noticed, 
but hardly understood, by George Hartmann in 
1544 ; it was better described by Fortuni Affaytatus 
in 1549, and by Martin Cortes in 1551 ; but it 
only became generally known through the labours 
of Robert Norman, a nautical instrument maker 
of Wapping, who began his experiments in 1576, 
and published an account of them in his " Newe 
Attractive," 1581. 

1 In his " Speculum Naturale," first published in Paris, 1473. 


Doubtless, owing to his other occupations, 
Galileo's researches in magnetism did not take 
him far. The main results are given in two letters 
to Curzio Picchena, Chief Secretary to the Grand 
Duke of Tuscany, dated i6th November and 
gth December 1607. From these we learn that 
he had made many experiments with loadstones, 
which resulted in his devising an armature by 
which the portative force of a stone could be con- 
siderably increased. He observed that the longer 
a stone sustains a weight the more it gains in 
strength. He also found that smaller stones were 
usually more powerful than larger ones. Thus, 
a small stone which he had picked up in Venice 
was much more powerful than one of 5 Ibs. belong- 
ing to his friend, Sagredo. This latter could 
normally sustain a weight of 6^ Ibs, but when 
provided with Galileo's armature it was capable 
of supporting more than 12 Ibs. By breaking up 
large stones and shaping the pieces in a certain 
way he was able to make each piece sustain thirty 
to forty times the weight borne by the original 
stone. The Abbe Castelli tells us in his treatise 
on the magnet (circa 1639-40) : 

" I have seen such a loadstone, only 6 ozs. in 
weight, armed with iron by the untiring industry of 
Signor Galileo, and presented to his Highness the 
Grand Duke Ferdinando, which lifts 15 Ibs. of iron 
worked into the shape of a sepulchre." l 

1 This form was probably suggested by the legend of Mohammed's 
coffin suspended in the air by loadstones. Sir Isaac Newton is said 
to have had a stone, set in a ring, which weighed only 3 grains, yet 
was able to support 746 grains. A Galilean stone and armature are 
now shown in the Tribuna di Galileo in Florence. 


Gilbert was one of the first persons who arrived 
at general, though confused, notions on the subject 
of gravitation. In his " De Magnete " he explains the 
influence of the earth upon the moon by comparing 
the former to a huge loadstone ; and in another 
work, not, however, published until many years 
after his death/ he gives his opinions at greater 
length. In this treatise he asserts that the earth 
and the moon act upon each other like two mag- 
nets, but the influence of the earth must be greater 
than that of the moon, on account of its greater 
mass. Again, although the influence is magnetic in 
it$ nature it does not show itself as in ordinary 
magnets, "It is not," he says, "so as to make 
the bodies unite like two magnets, but that they 
may go on in a continuous course/ 1 In another 
place he ascribes the tides partly to the influence 
of the moon. 

These speculations of the English philosopher 
had a strange fascination for Galileo. In 1608, he 
had the idea of recording their importance in a 
medal, which he proposed to strike on the occasion 
of the marriage of his pupil, Prince Cosimo, and 
the Archduchess Madeleine of Austria. Under 
the name, Cosmos, he proposed to engrave the 
figure of the prince, and a magnet from which 
depended several pieces of iron, with the mottoes : 
" Vim Facit Amor/' and " Magnus Magnes Cosmos." 

In the third " Day " of his Dialogues on the 
Ptolemaic and Copernican systems, published in 

1 " De Mundo Nostro Sublunari," Amsterdam, 1651. Gilbert died 
in 1603, aged 63. Leonard Digges and his son, Thomas, Gilbert's 
contemporaries, held the same view. 


1632, he utilises his own early magnetic observa- 
tions, and warmly acknowledges the merits of 
Gilbert's work, declaring that his marvellous 
conception of the earth as a great loadstone was 
to him a subject of praise, admiration, and envy. 
The passage is worth quoting : 

" I extremely praise, admire, and envy this 
author. I think him, moreover, worthy of the 
greatest praise for the many new and true obser- 
vations that he has made, to the disgrace of so 
many vain and fabling authors, who write, not from 
their own knowledge, but repeat everything they 
hear from the foolish vulgar, without attempting to 
satisfy themselves of the same by experiment 
perhaps that they may not diminish the size of their 

Here he is evidently tilting at the " Scientific" 
writers, numerous in his and the following century, 
who filled their books with fables about the all- 
embracing powers and virtues of the magnet, and 
on which charlatans traded and grew fat. One 
such person he appears to have met in Venice, of 
whom he gives an amusing account in the same 
Dialogues, at the end of the first " Day/' One 
of the speakers, Sagredo, commenting on the 
remarks of the previous speaker, says : 

"You remind me of one who offered to sell me 
a secret art, by which, through the attraction of a 
certain magnetic needle, it would be possible to 
converse across a space of two or three thousand 
miles. And I said to him that I would willingly 
become the purchaser, provided only that I might 
first make a trial of the art, and that it would be 
sufficient for the purpose if I were to place myself 


in one corner of the room and he in the other. He 
replied, that in so short a distance the action would 
be scarcely discernible ; whereupon I dismissed the 
fellow, saying that it was not convenient for me just 
then to travel into Egypt, or Muscovy, for the 
purpose of trying the experiment, but that if he 
chose to go there himself, I would remain in Venice 
and attend to the rest." 

During his residence at Padua Galileo was in 
the habit of returning to Florence for the long 
summer holidays. On these occasions for some 
years, and beginning about 1601, he gave instruc- 
tions in mathematics to the young prince, Cosimo 
(born 1590), there being, apparently, no one in 
Florence whom the Grand Duke thought capable 
of carrying on this branch of the boy's education. 
Galileo, of course, was duly sensible of the honour 
done in thus selecting him as the young prince's 
mathematical tutor ; and the arrangement was 
desirable for other reasons it added to his income, 
always a serious matter ; and it gained him the 
esteem and friendship of the reigning family of 
Tuscany, which, although not able (as we shall see) 
to protect him entirely from misfortunes, was still 
strong enough to make his troubles lighter than 
they would otherwise have been. 

While the Grand Duke was wont to declare 
that Galileo was the greatest mathematician in all 
Christendom, his wife, the Grand Duchess Cristina, 
believed him to be the greatest of astrologers, and 
at the commencement of wha? proved to be her 
husband's last illness, she begged him to correct his 
horoscope! He did so/ and communicated the 


result in a letter of i6th January 1609, according 
to which Ferdinando I. had still many years to 
live. Galileo's prognostic was speedily proved to 
be false, as the Grand Duke died twenty-two 
days after ! 

Florence, from the earliest period, was noted for 
its cultivation of the rites of sacrifice and divination, 
and during the thirteenth and fourteenth centuries, 
astrology was taught in the Universities of Italy, 
and in particular at Padua and Bologna. Even in 
the succeeding three centuries, and in spite of 
advancing knowledge, judicial astrology still held 
sway over the hopes and fears, not only of the vulgar, 
but of the highest and best educated classes. 1 

No wonder, then, if Galileo, more temporum, 
dabbled in horoscopes ; but it is not to be supposed 
that a mind, which early discarded the trammels of 
ancient sciences, and took nothing on trust or mere 
authority, could really have believed in them. We 
prefer to consider his action in this, and other 
instances, in the light of a pious fraud. 2 

Having brought our account of Galileo's public 
career up to the eve (1609) of his immortal discoveries 

1 Even grave astronomers and mathematicians were not exceptions. 
Thus, to mention only a few, Cardan, the algebraist, starved himself 
to death so that his prognostic as to that event should be fulfilled. 
Tycho Brahe and Kepler dabbled in the art, and the latter helped to 
maintain his family by casting nativities and publishing a yearly 
almanac, the prototype of our modern " Moore." Poor Kepler could 
not get his salary from the authorities at Prague, and so was driven 
to astrology, as the only thing that would pay, and on it he lived for 
years. Finally, Francis Bacon and Thomas Browne, typical wise 
men of England, thought that there was much truth in a sober and 
well-regulated astrology. 

2 For more on this subject see Favaro's "Galileo Astrologo 
secondo document! editi ed inediti," Trieste, 1881 ; or his '"Galileo e 
Suor Maria Celeste," p. 61. 



in astronomy, we must, before proceeding, retrace 
our steps and give some account of his private life. 

We have seen that by the death of his father, in 
1591, he had become the head of the family. This 
position, always attaching a grave responsibility to 
its possessor, was at this time, and particularly in 
the present case, fraught with much anxiety. Not 
only had Galileo, on his slender resources, to keep 
himself in Padua and provide for the requirements 
of the household in Florence, but it was his duty to 
see to his brother's setting out in life, and a still 
more sacred duty, to find a suitable husband for his 
unmarried sister, Livia. In Italy in those days, a 
girl's education being finished, two paths were open 
not always for her to choose. One led to the 
cloister, the other to the house of a husband. It 
had, apparently, been the family intention for Livia 
to take the veil, but so great was her aversion to a 
convent life, that her brother did not insist, much as 
the arrangement would have saved him in trouble 
and expense. 

Though his sister, Virginia, had been married to 
Benedetto Landucci before the father's death, the 
burden of providing the dowry had fallen on Galileo, 
who, pressed on all sides for money, had been 
unable immediately to pay the amount. At length, 
in May 1593, not choosing to wait any longer, and 
not caring who went short so long as he got his due, 
Landucci threatened to proceed to harsh measures 
in fact, to have Galileo arrested for debt the next 
time he set foot in Florence ! l 

1 " If you come here next month I shall be rejoiced to see you, 
only you must not come unprovided with funds, for I hear that 


Livia writing to her brother, ist May 1593, shows 
how all looked to him as to a Father Bountiful : 

" As our Lena 1 is going to join you in Padua I 
could not help sending by her these few lines to tell 
you about myself, and, though your lordship may 
not care to hear about me, I care to hear about you, 
for I have no one in the world but you. So please 
be so kind as to answer, that I may have that little 
bit of pleasure. Though your lordship writes to 
our mother, she never brings me your letters only 
says, 'Your brother sends his love.' She told me 
lately your lordship was going to send Michelangelo 
to Poland. I was at first extremely grieved at 
hearing this, but then I comforted myself by saying : 
4 If Galileo thought it was a dangerous place he 
would not send him/ for I know that you love him 
dearly. Besides that, I heard you were soon coming 
here, and it will seem a thousand years till you 
arrive! Please do remember to bring me some 
stuff to make a dress, for I am in great need of 

Galileo had some difficulty in giving his brother 
a start in life. He had desired for him some post at 
the Grand Ducal court, but there seemed to be no 
opening, though his musical talents and elegant 
manners had gained for him many friends in Florence. 
Early in 1593 he joined Galileo in Padua, in the 
hope of obtaining, if not permanent employment as 

Benedetto is determined to have his own, and menaces loudly that he 
will have you arrested the instant you arrive. He is just the man to 
do it, so I warn you, for it would grieve me much if anything of the 
kind were to happen." (Extract from Madam Giulia's letter to Galileo, 
dated 29th May 1593.) 

1 Nothing is known of this sister. She appears as Elena in the 
family genealogy, and is supposed by some biographers to have 
married and settled in Padua. Professor Favaro could find nothing 
to substantiate this story. 


a musician, at least some pupils from amongst the 
many foreign students of the University. Of the 
Polish scheme, to which Livia refers in the above 
letter, nothing is known beyond the fact that 
Michelangelo did go to Poland, but was soon 
back again on his brother's hands. At length, early 
in 1600, the offer of the Polish prince (name un- 
known) 1 was renewed on very favourable terms, and 
the young man set out on his second voyage in 
August of that year, provided with an outfit and 
money by Galileo. Michelangelo, with his " elegant 
manners/' would evidently be in his element there, 
for he was to have a place at the prince's table ; be 
dressed like the first gentlemen of his court ; have 
two servants to wait upon him ; a coach and four ; 
200 Hungary ducats yearly (about 300 Italian scudi) ; 
and perquisites ! 

Livia was by this time getting tired of convent life, 
and was plaguing her mother to find her a husband. 
Madam Giulia did so, and informed Galileo, upon 
whom of course would lie the burden of finding the 
dot. Replying on yth August 1600, he says : 

" From your letter and that of Mr Piero Sali, 
I hear of the proposed match for our Livia, as to 
which I do not see how I am to act, for, though 
from what Mr Piero says, I esteem it desirable, 
yet it is impossible for me to consent to it just at 
present The reason is this [here he enters into 
details of Michelangelo's Polish engagement, and 
goes on], I of course must provide him with money, 
and besides, the prince wishes him to bring certain 
things ; so that what with these articles and what 
he requires for himself, I cannot avoid spending less 

1 Probably one of the Radziwil family. 


than 200 scudi. Now, you know what expenses I 
have had this last year, so that I really cannot do 
as I would. On the other hand, Sister Contessa 
[Superioress of the Convent St Giuliano] writes 
that on all accounts I ought to take Livia away 
from the convent, as she hates remaining there. 
Now, as she has waited so long, I should like her 
to be well and comfortably settled. If I am to 
believe Sr. Piero, this Pompeo Baldi [the selected 
bridegroom] is a good sort of man, yet hearing that, 
including his private income, he has not 100 ducats 
yearly, I do not see how a household is to be main- 
tained on that sum. Therefore I would, if possible, 
have the matter deferred. Michelangelo will, with- 
out fail, send me a good sum of money as soon as 
he gets to his destination, and with this, joined to 
what I can get together, we may take measures for 
establishing the child, since she too is determined to 
come out and partake of the miseries of this world. 
Meanwhile, I wish you would see about taking her 
away from St Giuliano and placing her in some 
other convent till her turn comes, and persuade her 
that she will lose nothing by waiting. Tell her 
that there have been queens and great ladies who 
have not married till they were old enough to be her 
mother. Therefore, pray see her as soon as you 
possibly can, and give the enclosed letter to Sister 
Contessa. She has been asking me to pay what is 
due for Livia's board. Find out the amount, and I 
will send it at once." 

Depending on his brother's promised help in 
meeting Livia's dowry, Galileo made up a new 
match between her and a Pisan gentleman, Taddeo 
Galletti, on ist January 1601, promising a dot of 
1800 ducats, of which 600 ready cash, and a 
trousseau (worth 200), were to be paid down, and the 
rest to be paid within five years. But of this 800 he 


had to borrow 600, relying on his brother's assur- 
ances of a speedy remittance from Poland. Vain 
hopes! Livia had been married nearly a year, 
and Michelangelo had neither repaid the money 
advanced for his own outfit, nor contributed to 
his sister's dowry. Writing to him 2Oth Novem- 
ber 1 60 1, Galileo thus expresses his resentment of 
such ungrateful conduct : 

" Though you have sent no answer whatever to 
any of the four letters which I have written within 
the last ten months, I nevertheless write and repeat 
what I have said. I would rather think that all my 
letters had missed you, or any other unlikely thing, 
than that you meant to be wanting in your duty not 
only in answering my letters, but in sending money 
to pay the debts which we owe to various persons, 
and in particular to Signor Taddeo Galletti, our 
brother-in-law. If I had imagined things were 
going to turn out in this manner, I would not have 
given the child in marriage, or else I would have 
given her only such a dowry as I was able to pay 
myself without assistance, since I seem to be fated 
to bear every burden alone. I beg that you will, 
without delay, have a deed drawn out and wit- 
nessed by a public notary, in which there shall be 
an acknowledgment of your being bound to pay 
the said dowry to Signor Taddeo jointly with me. 
I insist on this being done without delay, and, 
above all, I desire that you will write and give 
some news of yourself, for every one is feeling 
anxious about you, there having been no word of 
your whereabouts since you left Cracow." 

Michelangelo never paid a farthing for years, 
and then only a small fraction (50 crowns) of what 
he owed. In 1605 he was back again in Padua, 


living at Galileo's expense, till the latter succeeded 
in getting him a post as music master in the court 
of the Duke of Bavaria. That he should spend 
his gains upon himself and, when spent, fall back 
upon his brother, seemed to him a matter of course. 
Selfish as he was conceited, never from first to last 
could he be brought to see that, when he had more 
than enough for his legitimate expenses, the helping 
of relations became at once a sacred duty. 

For cool effrontery and heartless cynicism the 
following letter of 4th March 1 608, to Galileo, is, we 
hope, not often paralleled : 

" I was glad to get your letter, and, though it 
was full of complaints, still I am pleased to find that 
you do not despise me quite so much as I had 
imagined. Now I will answer you about the claims 
of our brothers-in-law. My dear brother, if I have 
not been able to pay them as I certainly should 
have liked to do, I do not see that you can blame me 
so much. You complain of my having spent such 
a large sum of money on one feast ; I do not deny 
that the sum was large, but just consider that it was 
on the occasion of my wedding. There were more 
than eighty persons present, among whom were 
many gentlemen of importance, and among these 
there were no less than four ambassadors. Had I 
not followed the custom of the country, I should 
have been put to shame, so that I was forced to 
spend what I did, and indeed could not possibly 
have managed with less. You cannot accuse me 
of ever having spent such sums of money simply 
for my own gratification, never, indeed, have I 
thrown money away on anything, but, on the 
contrary, have often denied myself what I wanted 
in order to save. You say that it does not serve 
your turn for me to write and tell you that * God 


will not be pleased if you keep up a feeling of 
rancour against me/ Of course, I know it will not 
serve your turn ; I did not write it supposing that 
it would help you to get rid of the debt to our two 
brothers-in-law. As to that matter, I tell you 
shortly that I will do what I can, and, indeed, will 
put myself to every inconvenience rather than not 
satisfy their claims in part; but as to my finding 
1400 crowns, which is the sum still remaining to be 
paid, I know that I cannot do it, and never shall, 
for I find it scarcely possible to pay the interest. 
You should have given our sisters a dowry, not 
merely in conformity with your own ideas of what 
was right and fitting, but in conformity with the 
size of my purse. God knows that if I have not 
paid off my share it is because I could not. When 
I sent you those 50 crowns, Signor Cosimo lent 
me 30 of them, and I have not yet repaid him, 
though I must soon, as he writes saying he wants 
one of my lutes! By and bye I will borrow 
another 50 crowns and send you. I cannot 
promise more, since for these last few months I 
have been obliged to spend a great deal on my 
house. I know you will say that I should have 
waited and thought of our sisters before taking a 
wife. But, good heavens ! the idea of toiling all 
one's life just to put by a few farthings to give one's 
sisters ! This joke would be indeed too heavy and 
bitter, for I am more than certain that in thirty 
years I could not have saved enough to cover this 
debt. God help me ! I would do more if I could. 
Have a little pity on me and consider ; you cannot 
say that I ever had the heart to gratify my own 
liking without caring about others. You may say 
that my having married is a proof that I care not 
for paying my debts as long as I can gratify my 
own liking. To this I shall make no answer. God 
knows I am thankful to have my wife, and I hope 


He will enable me to carry out my desire in satis- 
fying this debt. I shall say no more, but I trust 
you will consider me a good brother, for I will do 
all I can to send you some assistance, since you say 
it is all my fault that you are in such distress. But 
excuse me, if I failed hitherto it was because I 
could not help it. 

" I understand that you are going to send the 
case of lutes shortly. I have been expecting its 
arrival with some impatience ; for during this Lent 
I am in great want of them for playing concerted 
music, and to have them quicker I would not mind 
paying something more for the carriage." 

Galileo must have been more than human not to 
feel some resentment at the selfishness displayed in 
this rambling epistle, H is anger, however, was short- 
lived. In 1610, the brothers had again resumed 
their correspondence, and from that time Michel- 
angelo never failed, as we shall see, to write whenever 
he wanted his brother's assistance. The 50 crowns 
mentioned in his letter are probably all that he 
ever paid to his long-suffering brother. 

As if the worries and burdens of his father's 
family were not enough, Galileo must needs add 
to them the cares of a family of his own. In 1599, 
he entered into amorous relations with a Venetian 
lady, Marina Gamba, by whom he had three 
children, Virginia, born I3th August 1600; Livia, 
born 1 8th August 1601 ; and Vincenzio, born 2ist 
August 1606. 



EARLY in the month of October 1 608, the telescope 
was invented in Holland, and, according to all 
accounts, its discovery was the result of an accident. 
Long ago Epicurus defined the universe and all 
that it contains as the result of a fortuitous con- 
course of atoms, and so it is very often in the 
arts and sciences of man, great discoveries are the 
result of the fortuitous juxtaposition of two and 
two. In the present case, and as the story goes, 
an apprentice, playing with spectacle lenses in the 
shop of one Hans Lipperhey, an optician of 
Middleburg, noticed that by holding two of them 
in a certain position a large and inverted view of 
objects was obtained. On hearing of this the 
master fixed two glasses in a tube, so that the 
weather-cock on a neighbouring church spire could 
be seen apparently nearer and upside down. This 
toy was shown in his window, where one day the 
Marquis Spinola chanced to see it, and entered 
the shop to examine it. Struck by the strange 
phenomenon it presented, he purchased the instru- 
ment, and afterwards gave it to Prince Maurice of 

Portrait of Galileo, aged about 40. 

[To face p. 74. 


Nassau, who thought it might be useful in military 

Among the Acts of the States-General pre- 
served at the Hague, Professor Van Swinden found 
some interesting papers relating to this matter. 
On 2nd October 1608 the States Assembly took 
into consideration a petition of Lipperhey for the 
exclusive right of making and selling an instrument 
for seeing at a distance. They suggested that the 
instrument should be arranged so as to enable one 
to look through it with both eyes. A trial was 
fixed for the 4th October, and it was resolved that, 
if it should be found useful, an engagement should 
be entered into with the inventor to make three 
such instruments of rock crystal, and that he 
should be bound not to divulge the secret to 
anybody. The trial on the 4th was apparently 
satisfactory, for two days later the Assembly 
voted Lipperhey 900 florins. On i5th December 
they examined his arrangement of the instrument 
" to see with both eyes," and approved it ; but, as 
others by this time had a knowledge of the in- 
vention, they refused to grant him the exclusive 
privilege of making and selling it. They, how- 
ever, gave him an order to make, for the use 
of the Government, two other instruments " to 
see with both eyes," allowing him the same 
remuneration as in the first instance. 

Of the others referred to above, one was 
James Metius of Alkmaer, who claimed the in- 
vention in a petition, dated I7th October, or 
fifteen days after Lipperhey. In this petition he 
declares that the idea occurred to him accidentally 


while engaged on other experiments, and that he 
had now succeeded so far in perfecting his in- 
vention "as to make distant objects appear as 
distinct by it as by the instrument which had 
lately been offered to the States/' Apparently 
the instrument of Metius was not so good as he 
said, for he was advised to bring it to greater 
perfection, when his petition for a privilege would 
be taken into consideration. 

Very soon a third claimant appeared in the 
person of Zacharias Jansen, also an optician and 
a near neighbour of Lipperhey. As regards this 
claim, the truth would seem to be that Jansen, as 
far back as 1590, had really constructed the 
microscope ; and that, on hearing of Lipperhey's 
invention, he adapted his own instrument from 
seeing things near to seeing things at a distance; 
and so he was able, with some show of reason, to 
claim the invention. 1 

Leaving this part of the subject, the fact for 
us at present is that reports of the invention, 
more or less vague, spread slowly over Europe, 
and reached our philosopher while on a short 
visit to Venice about the middle of June 1609. 
As Galileo's independent invention of the tele- 
scope, like so many more of his discoveries, has 
been denied or belittled by envious detractors in 
his own and later times, the story had best be 
told in his own words. In a letter from Venice 
to his brother-in-law Landucci, dated 29th August 
1609, he says : 

1 For more on this subject see Professor Moll's paper in Journal, 
Royal Institution^ vol. i. pp. 3 19 and 483. 


" I write now because I have a piece of news 
for you, though whether you will be glad or sorry 
to hear it I cannot say, for I have now no hope 
of returning to my own country, 1 though the oc- 
currence which has destroyed that hope has had 
results both useful and honourable. You must 
know then that about two months ago \i.e. about 
June 1609] a ^port was spread here that in 
Flanders a spy-glass had been presented to Prince 
Maurice, so ingeniously constructed that it made 
the most distant objects appear quite near, so 
that a man could be seen quite plainly at a 
distance of 2 miles. This result seemed to me 
so extraordinary that it set me thinking, and as 
it appeared to me that it depended upon \ the laws 
of perspective, I reflected on the manner of 
constructing it, and was at length so entirely 
successful that I made a spy-glass which far sur- 
passes the report of the Flanders one. As the 
news had reached Venice that I had made such 
an instrument, six days ago I was summoned 
before their Highnesses, the Signoria, and ex- 
hibited it to them, to the astonishment of the 
whole sdnate. Many of the nobles and senators, 
although of a great age, mounted more than once 
to the top of the highest church tower in Venice, 
in order to see sails and shipping that were so 
far off that it was two hours before they were 
seen, without my spy-glass, steering full sail into 
the harbour; for the effect of my instrument is 
such that it makes an object 50 miles off appear 
as large as if it were only five. 

" Perceiving of what great utility such an 
instrument would prove in naval and military 
operations, and seeing that his Serenity the Doge 
desired to possess it, I resolved on the 24th 

1 A design which he had formed earlier in the year. See 
p. 1 1 6 infra. 


inst. to go to the palace and present it as a 
free gift. On quitting the presence-chamber I 
was commanded to bide awhile in the hall of 
the Senate, whereunto the Procurator, Antonio 
Prioli, one of the heads of the University of 
Padua, came, and, taking me by the hand, said 
that the Senate, knowing the way in which I 
had served it for seventeen years at Padua, and 
being sensible of my courtesy in making it a 
present of the spy-glass, had ordered my election 
(with my good-will) to the Professorship for life, 
with a salary of 1000 florins yearly; and as 
there remained yet a year to terminate the 
period of my last re-election, they willed that 
the increase of salary should date from that 
very day. 1 Knowing that Fortune's wings are 
swift but that those of Hope are drooping [i.e. 
the hope of returning and settling in Florence], 
I said I was content to abide by his Serenity's 
pleasure. Then the illustrious Prioli, embracing 
me, said : ' As I command here and can order 
what I please (it being my turn this week), I 
will that after dinner the Senate assemble, and 
that your election be put to the ballot/ which 
was done [with few dissentient votes.] So I 
am bound here for life, and can only hope 
to enjoy a sight of my own country during the 

1 The decree is dated 2^th August 1609, and the preamble 
runs as follows : " Domino Galileo Galilei having been mathe- 
matical lecturer in Padua for seventeen years, to the gain of the 
University and to the satisfaction of all ; and having during his 
professorship made known to the world divers discoveries and 
inventions to his own renown and the common weal; but in 
particular having lately invented an instrument by which (knowing 
the secrets of perspective) things visible, b ( ut most distant, are 
brought within easy vision, and which may be made to serve in 
many occasions ; now, it is proper that this Council do gratefully 
and munificently recognise the labours of those who are employed 
for the public benefit. Therefore," etc. 

Campanile and Church of San Marco, Venice. 

[To face p. i 


In "II Saggiatore," published in 1623, 
Galileo enters more fully into the reasonings 
which led him to the invention, and defends his 
right to consider the telescope as a child of his 
brain. He says : 

"What part belongs to me in the invention 
of the telescope, and why may I reasonably call 
it my son? As I have long ago shown in my 
* Sidereus Nuncius/ news arrived at Venice, 
where I happened to be at the moment, that 
a Dutchman had presented to Count Maurice 
of Nassau a glass by means of which one could 
see distant things as clearly as if they were 
near. With this simple fact I returned to 
Padua, and, reflecting on the problem, I found 
the solution on the first night after my arrival, 
and the next day I made an instrument and 
reported the fact to my friends at Venice, with 
whom I had been discussing the rumour. In 
the next six days I made a more perfect instru- 
ment, with which I returned to Venice, and 
showed it for more than a month to the wonder 
and astonishment of the chiefs of the republic 
a task which caused me no small fatigue. 
But perhaps it may be said that no great credit 
is due for the making of an instrument, or the 
solution of a problem, when one is told before- 
hand that the instrument exists, or that the 
problem is solvable. It may be said that the 
certitude of the existence of such a glass aided 
me, and that without this knowledge I would 
never have succeeded. To this I reply, the help 
which the information gave me consisted in 
exciting my thoughts in a particular direction, 
and without that, it is possible they may never 
have been directed that way; but that such 
information made the act of invention easier to 


me I deny, and I say more to find the 
solution of a definite problem requires a greater 
effort of genius than to resolve one not specified ; 
for in the latter case hazard, chance, may play 
the greater part, while in the former all is the 
work of the reasoning and intelligent mind. 
Thus, we are certain that the Dutchman, the 
first inventor of the telescope, was a simple 
spectacle-maker, who, handling by chance different 
forms of glasses, looked, also by chance, through 
two of them, one convex and the other concave, 
held at different distances from the eye ; saw 
and noted the unexpected result; and thus found 
the instrument. On the other hand, I, on the 
simple information of the effect obtained, dis- 
covered the same instrument, not by chance, 
but by the way of pure reasoning. 1 Here are 
the steps : the artifice of the instrument depends 
either on one glass or on several. It cannot 
depend on one, for that must be either convex, 
or concave, or plain. The last form neither 
augments nor diminishes visible objects ; the 
concave diminishes them, the convex increases 
them, but both show them blurred and indistinct. 
Passing then to the combination of two glasses, 
and knowing that glasses with plain surfaces 
change nothing, I concluded that the effect could 
not be produced by combining a plain glass 
with a convex or a concave one ; I was thus 
left with the two other kinds of glasses, and 
after a few experiments I saw how the effect 
sought could be produced. Such was the march 
of my discovery, in which I was not assisted in 

1 This is exactly what Huygens, writing years afterwards, seems 
to deny. "I would place, 35 he says, "without hesitation above all 
mortals him who by reflection alone, and without the aid of chance, 
should arrive at the invention of the telescope." "Dioptrica," 


any way by the knowledge that the conclusion 
at which I aimed was a verity. 

" But some people believe that the certainty of 
the result aimed at affords great help in attaining 
it. Let them read history, and they will find that 
Archites made a dove that could fly, and that 
Archimedes made a mirror that burned objects at 
great distances, and many other admirable machines. 
Now, by reasoning on these things such people, 
doubtless, will be able, with very little trouble and 
with great honour and advantage, to tell us how they 
were constructed. And even if they do not succeed, 
they will be able to certify for their own satisfaction 
that that ease of fabrication which they had promised 
themselves from the foreknowledge of the result is 
very much less than what they had imagined." 

Of the first telescope referred to in the above 
extracts no further mention is made, so we may 
suppose that it was of little value ; but the second, 
which he presented to the Doge and is unfortunately 
lost, is mentioned with some particulars in his 
"Sidereus Nuncius," published at Venice about the 
middle of March 1610. It consisted of a leaden 
tube, with a plano-concave eye-glass and a plano- 
convex object glass, and had a magnifying power of 
3 diameters, thus making objects appear three times 
nearer, and consequently nine times larger. From 
other sources we learn that the tube was about 70 
centimetres long and about 45 millimetres diameter. 
This instrument was shown for the first time in 
public on 2 ist August 1609, from the top of the 
campanile of San Marco, when the farthest object 
that could be clearly seen was the campanile of the 
Church of San Giustina in Padua, distant about 
35 kilometres in a straight line. 





The principle of Galileo's telescope is illustrated 
in the adjoining diagram. C is the centre of the 
object-glass, and c that of the eye-glass ; the 
former being a convex, the latter a concave lens. 
The direction of the line cC may be spoken of as 
the axis of the telescope. It will be readily under- 
stood that if the instrument be adjusted so that its 
axis points in the direction of a minute object s', 
then, on applying the eye to the eye-glass, that object 
appears exactly in the centre of the field of view. 

Fig. 6. 


The eye placed at E will see the point s ; in the 
same direction as if the two intervening lenses were 
suddenly annihilated. To fully realise the pheno- 
menon of vision through the telescope, we must 
examine the course of the rays of light which reach 
the eye from an object slightly removed from the 
axis of the telescope. Such an object is repre- 
sented by S in the figure, Rays of light emanate 
from this point in all directions ; we are concerned, 
however, only with those which strike the object- 
glass between P and Q. These rays pass through 
both lenses, being refracted each time. The convex 

1 For convenience in drawing the breadth of the telescope is 
enlarged out of proportion to its length. 


lens bends them inwards, so that they would all, if 
subsequently uninterrupted, very nearly meet at 
about the point F in the figure. But before reach- 
ing this point they are intercepted by concave lens, 
which turns their course outwards again. The 
final result will, provided the distance cC between 
the two lenses be suitably adjusted, be a beam of 
parallel rays, as indicated in the figure. To a 
beam of parallel (or, it may be, very slightly diver- 
gent) rays the human eye is sensible ; so that the 
beam of rays represented by pp ; , qq', and the space 
between them, would on entering the eye render 
visible the small luminous object S from which they 
originally came. And as the apparent direction of 
this object depends entirely on the direction in 
which the rays were last travelling before entering 
the eye, the object S will be seen in the direction of 
the broken line EA, the dotted line ER being 
inserted to show the direction in which the same 
object would have been visible but for the inter- 
vention of the telescope. The effect of this is 
that the apparent distance of S and s ; from one 
another is increased about three times by the use of 
the instrument, which we may accordingly say has 
a magnifying power of 3 diameters. 

In the diagram the objects examined, S and s', 
have for obvious reasons been placed near the con- 
vex lens. But if the telescope be directed to two 
stars, near one another in the heavens, but both of 
course at practically infinite distances from the 
observer, the phenomena are exactly as described 
above, although the concave lens would require to 
be pushed slightly into the main tube in order that 


the rays of light from the stars, after passing down 
the telescope, may finally emerge parallel. At the 
same time, the change of distance of an object 
observed will slightly affect the magnifying power. 

On his return to Padua Galileo made his third 
telescope, of which he only says that "it made 
objects appear more than sixty times larger," which 
is equivalent to a magnifying power of about 8 
diameters. But in a very few days he had a much 
better one, which enlarged four hundred times. With 
this he made his first observations on the moon, 
which he " brought to a distance of less than 3 
semi-diameters of the earth, thus making it appear 
about twenty times nearer and four hundred times 
larger than when seen by the unaided eye." He 
also turned it towards Jupiter, but with no specified 
results. To obviate the shaking when held in the 
hand, the instrument was firmly fixed on a support. 
The lenses were adjustable, the tubes which held 
them being capable of being drawn out of, or 
pushed into, the main tube. Thus, to see clearly 
things not very distant, the glasses should be drawn 
apart a little; while for very distant objects they 
had to be approached. He found he could grind 
large convex lenses more truly than small ones. 
He preferred therefore to make his object-glasses 
larger than necessary, and to cover a portion of 
their surface, leaving open around the centre just 
so large a space as he found, on testing, to give 
the best results. 

While on a short visit to Florence, probably 
in October 1609, he had this instrument with him, 
and showed it to his late pupil, Cosimo II., now 


become Grand Duke, "who, to his great surprise 
and delight, was able to see that the moon was 
a body very similar to the earth." 

Very early in January 1610, Galileo had con- 
structed a fifth and still more powerful telescope, 
" sparing neither labour nor expense/' which showed 
objects more than thirty times nearer and nearly 
one thousand times larger. 1 With this instrument 
he not only verified and completed his observations 
on the moon, begun the previous autumn with his 
fourth telescope, but he also discovered Jupiter's 
moons, some of the fixed stars, and contributed 
to the solution of that long-standing puzzle to 
philosophers the Milky Way. 

Writing to Belisario Vinta, then with the 
Tuscan Court at Pisa, 3oth January 1610, Galileo 
thus modestly alludes to his first series of dis- 
coveries : 

" I am at present staying in Venice for the 
purpose of getting printed some observations which 
I have made on the celestial bodies by means of 
my spy-glass (mio occkiale) and which infinitely 
amaze me. Therefore do I give thanks to God, 
who has been pleased to make me the first observer 
of marvellous things unrevealed to bygone ages. 
I had already ascertained that the moon was a 
body very similar to the earth, and had shown 

1 Galileo arrived at the powers of his glasses by the following 
crude method. " Place," he says, " upon a wall at a certain distance 
two unequal discs, one of which you will observe with the telescope 
and the other with the naked eye. If the disc seen through the 
telescope appear equal to the other, the magnifying power of the 
instrument is in the proportion of the two discs. If they do not 
appear equal the * other J disc must be enlarged or diminished until 
they do, and then the magnifying power will be, as before, in the 
proportion of the discs." 


our Serene Master, the Grand Duke, as much, 
but imperfectly, not then having such an excellent 
spy-glass as I now possess, which, besides showing 
the moon most clearly, has revealed to me a 
multitude of fixed stars never before seen, being 
more than ten times the number of those that can 
be seen by the unaided eye. Moreover, I have 
ascertained what has always been a matter of con- 
troversy among philosophers, namely, the nature 
of the Milky Way. But the greatest marvel of 
all is the discovery of four new planets. I have 
observed their motions proper to themselves and 
in relation to each other, and wherein they differ 
from the motions of the other planets. These new 
bodies move round another very great star, in the 
same way as Mercury and Venus, and, perad- 
venture, the other known planets, move round the 
sun. As soon as my tract is printed, which I 
intend sending as an advertisement to all philoso- 
phers and mathematicians, I shall send a copy to 
his Highness, the Grand Duke, together with an 
excellent spy-glass, which will enable him to judge 
for himself of the truth of these novelties." 

The tract referred to in the above letter is his 
" Sidereus Nuncius" (Messenger of the Stars), the 
preface of which is dated 4th March 1610, and the 
book, doubtless, appeared immediately after, say, 
towards the middle of March. In this epoch- 
marking treatise he gives the results of his obser- 
vations to date, of which we proceed to give a 

His observations were first directed to the moon. 
The discovery of new spots on its face, added to 
those already visible to the naked eye, and observa- 
tions on the changes of light on those spots, led him 


to the conclusion that the surface of the moon, far 
from being smooth and polished, according to the 
opinion of the ancients, was rough with deep de- 
pressions and high mountains. Those parts which 
remained or became brilliant he inferred were land, 
like the solid parts of this earth, while those which 
remained obscure the permanent spots were 
water. The illuminated edges of the moon in all its 
phases showed themselves perfectly round, without 
those indentations which one would expect from the 
inequalities of its surface. Galileo explained this 
appearance (i) by supposing that the mountainous 
parts, as it were, masked each other, so that at the 
distance of the earth the intervening depressions were 
not discernible, and (2) by the existence of a lunar 
atmosphere of a density such as to reflect the solar 
rays while not obstructing the vision. Thus the 
reflection of solar light by this atmosphere gave 
the appearance of a regular circular contour, only 
intensified in the parts most illuminated. From 
the appearance of illuminated mountain-tops in 
the dark part of the moon at some little distance 
from the broken line along which sunrise or 
sunset was general, he was able to judge of the 
height of some of these mountains. And his calcu- 
lation agrees very well with the modern estimate. 
The higher mountains were found to rise 4 or 5 
miles above the general level a height which is 
seldom exceeded on the earth. 

He, of course, remarked the feeble light, so- 
called phosphorescent, which, in the first and last 
quarters of the moon, makes visible to us that part 
of its disc which is no longer illuminated directly by 


the sun. After showing that this light 1 did not 
originate in the moon itself, and was not reflected 
there from Venus, he concludes that it can only be 
due to the sunlight reflected from the earth to the 
moon, and thence reflected back to our eyes. 1 

After referring for greater details to the work 
which he proposed to publish on the system of the 
world, he contends, contrary to the received opinion, 
that our earth is a moving planet, and that it exceeds 
the moon in luminosity, and, therefore, that it is 
far from being the sink of impurity hitherto 

In examining the fixed stars and comparing them 
with the planets, Galileo discovered a remarkable 
difference. While the planets showed themselves as 
discs like little moons, the stars appeared no larger 
than they do to the naked eye, bright specks in the 
firmament, sending forth twinkling rays. In ex- 
planation of this fact he supposes that the telescope 
has the effect of stripping the star of the false light 
by which it is surrounded when viewed with the 
naked eye. This spurious corona is ascribed by him 
to the effect of irradiation which generally increases 
with the brightness of the field upon which the 
luminous object is projected. Thus, at sunset, when 
the obscurity of the heavens is tempered by the 
twilight, the stars, even of the first magnitude, 
appear very minute. So, with respect to Venus, 
notwithstanding her usual splendour, she does not 

1 Leonardo da Vinci and Maestlin had already arrived at the 
same conclusion , but da Vinci's writings were certainly not known to 
Galileo (see p. 23 ante\ and Maestlin's opinion probably not, as 
knowledge in those days did not spread fast, except in special 


exceed a| star of the sixth magnitude on those 
occasions when she happens to be, visible at 

noon. 1 

Upon directing his telescope to the more con- 
spicuous star-clusters, he was astonished to find 
that they contained, besides those already known, 
a great number of other stars too faint to be in- 
dividually recognised by the naked eye. The 
number of the Pleiades, which had been fixed at 
seven, now rose to forty, while in the constellation 
of Orion, instead of seven he counted eighty stars. 
Certain portions of the Milky Way were resolved 
into a countless number of minute stars ; and he 
inferred that as a whole it derived its singular white- 
ness from innumerable other stars which his instru- 
ment was not powerful enough to separate* 

When Galileo turned \usfourth telescope to the 
planets, he saw them as little moons. Jupiter's disc 
was of considerable magnitude, but in no other way 
did he differ from the other planets. Now, on 
7th January 1610, directing his fifth and more 
powerful glass towards Jupiter, his attention was at 
once drawn to three small but very bright stars that 
appeared in his vicinity, two on the east side and 
one on the west. He at first imagined them to be 
fixed stars, and yet there was something in their 
appearance which he thought curious. They were 
all disposed in a right line parallel to the plane of 
the ecliptic, and were brighter than other stars of the 
same magnitude. 2 This did not, however, induce 

1 He has a great deal more on this subject of irradiation in his 
letters to Griemberger on Lunar Mountains ; in his work on " Sun- 
Spots," and " II Saggiatore." 

2 See attached facsimile of Galileo's notes of these observations. 


him to alter his opinion that they were fixed stars, 
and therefore he did not note their distances from 
each other or from the planet. Happening, by mere 
accident, as he says, to examine Jupiter again on 
8th January, he was surprised to find that the stars 
were now arranged quite differently. They were 
all on the west side, and were nearer to each other 
than on the previous evening, and at equal distances 
apart. The strange fact of the mutual approach of 
these stars had as yet no significance for him ; it 
only excited his astonishment that the planet should 
be seen to the east of them all when on the previous 
night it was to the west of two of them. He very 
soon began to think that perhaps the motion of 
Jupiter might be direct, contrary to the accepted 
opinion of astronomers, and that he had got in 
advance of the stars. He therefore waited for the 
following night with some anxiety, but he was dis- 
appointed, for the heavens were enveloped in 
clouds. On loth January he could see only two 
stars, and they were both on the east side! He 
suspected that the third might be concealed behind 
the disc of the planet. Those visible appeared as 
before in the same right line, and lay in the direction 
of the ecliptic. Unable to account for such changes 
by the motion of the planet, and being at the same 
time fully assured that he always observed the same 
stars, his doubts now turned into admiration, and 
he concluded that the motions must be referred 
to the stars themselves and not to the planet. He 
therefore determined to watch them with the closest 

On nth January he again saw only two stars, 

Facsimile &U>ichcs uf lupikr's Sotelliitt (from Gulilco's MSS.). 


still on the east side of Jupiter, but the outer one 
was now nearly twice as large as the other, 
although on the previous night they were almost 
equal. This fact, taken in connection with the 
constant change of the relative positions of the 
stars and the total disappearance of one of them, 
left no doubt on his mind of their real character 
He concluded that there are in the heavens three 
stars revolving round Jupiter in the same way as 
Venus and Mercury revolve round the sun. On 
1 2th January he again saw three stars, two on 
the east side of Jupiter, and one on the west. 
The third began to appear about three o'clock 
in the morning, emerging from the eastern limb 
of the planet ; it was then very small, and dis- 
cernible only with great difficulty. On i3th 
January he saw four stars, three of them on 
the west side and one on the east. They were 
all in a line parallel to the ecliptic, with the 
exception of the central one of the western group, 
which was a little towards the north. They 
were all about the same size, and shone with a 
much greater lustre than fixed stars of the same 
magnitude. January i4th was cloudy, but next 
night he saw all four stars to the west of the 
planet, all nearly in the same right line, and 
increasing in size and brilliancy, according to their 
distance from Jupiter. 

And so he continued nightly, up to 2nd March 
1610, to make these observations, sixty-six of which 
are figured and described in the "Sidereus 

The persistence of the relative distances between 


these four bodies and Jupiter in all their changes 
left no room for doubt that they accomplished 
with him, and in about twelve years, a revolu- 
tion around the sun as a centre. Their own 
orbits round the planet were unequal in time, 
those nearest moving more rapidly than those 
more remote; while the most remote of all 
appeared to complete its revolution in one-half 
month. 1 

"It is now/' he says in conclusion, "not simply 
a case of one body (the moon) revolving around 
another body (the earth), while the two together 
make a revolution around the sun, as the Coper- 
nican doctrine teaches; but we have the case of 
four bodies or moons revolving round the planet 
Jupiter, as the moon does round the earth, while 
they all with Jupiter perform a grand revolution 
round the sun in a dozen years." 

By the ist of January 1610 Galileo had fitted 
up his workshop, so as to be able to make and 
grind his own glasses, of which he turned out 
large numbers, but of which only a small per- 
centage was found to be of any great value. 
Thus, by the middle of March, out of one 
hundred and more which he had ground "at 
great fatigue and expense," only ten were able 

1 Two years later, in the opening passages of his " Discourse on 
Floating Bodies," he gives the periods of revolution approximately 
as follows : The innermost one, i day 18 hours 30 minutes ; the 
second, 3 days 13 hours 20 minutes ; the third, 7 days 4 hours ; and 
the fourth or outermost, 16 days 18 hours. The modem figures are 
in days, hours, minutes, and seconds, i, 18, 28, 36; 3, 13, 17, 54; 
7> 3> 59> 36; and 16, 18, 5, 7, respectively. A fifth satellite was dis- 
covered in 1892, whose period is only n hours and 57^ seconds. 
Jupiter's belts were discovered by Torricelli, a disciple of Galileo. 


to show the newly discovered moons of Jupiter 
and the fixed stars. 1 The object glasses gave 
him the most trouble, as it is easy to understand, 
since everything depends on the degree of 
accuracy with which this glass brings to a focus 
the rays of light passing through it. 

The same difficulty was found elsewhere, for 
Kepler, in one of his letters about this time, tells 
Galileo that it was easy to find good concave 
lenses in Germany, but that he found it most 
difficult to procure decent convex ones. In fact, 
for a long time no instruments at all approaching 
Galileo's were to be had in Europe, and he was 
consequently besieged with orders from all parts. 
Thus, Daniel Antonini, writing from Brussels in 
April 1611, complains that in all Flanders no instru- 
ment was to be had capable of magnifying more 
than five times, and says that he was obliged to 
make one himself, which was able to show " fairly 
well the inequalities of the moon's surface and the 
Medicean stars." 2 As late as 1634 a good instru- 
ment could not be procured in Paris, Venice, or 
Amsterdam ; and even in Holland, the home of 
the telescope, down to 1637, there was not one 
which could show Jupiter's disc well defined. 3 

1 Letter to Vinta, igth March 1610. At this time his clever workman 
Mazzoleni. was also engaged not only on the geometrical and military 
compass, of which many hundreds were made and sold all over 
Europe, but on hydrostatic balances, air thermometers, magnets and 
magnetic compasses for ships, and various kinds of drawing com- 
passes for engineers and architects. He had also added a printing- 
press, where his tract on the Geometrical and Military Compass was 
set up. See pp. 43-44 ante. 

2 I.e. Jupiter's satellites, see p. 96 infra. 

3 Galileo continued all these years to grind his own glasses, and 
it was not until his eyesight began to fail that he consented to 



It detracts little from the merit of Galileo's 
invention that the modern refracting telescope is 
based upon a different combination of lenses than 
that which he used, After possessing himself of 
one of Galileo's instruments, Kepler designed, 
though he did not make, a telescope consisting 
of two convex lenses. The difference between the 
two systems can be seen by comparing the adjoin- 
ing diagram with that of Galileo's telescope already 

Fig. 7. 


given. Without entering into a detailed description, 
it may be well to point out that in Galileo's the 
rays of light which travel from the point S and 
penetrate to the observers eye do not, on striking 
the object-glass, cover the whole of its surface ; 

impart his secret to Ippolito Mariani, commonly known as II Tordo, 
whom he appointed as his successor in the art. From about 1637, 
Francesco Fontana of Naples also began to turn out good glasses of 
the Galilean pattern. After Galileo's death Torricelli, having devised 
an improved way of grinding and polishing lenses, of which he was 
the first to calculate previously the curve, made some instruments of 
great perfection. Gradually other Italians took up the art, and 
became noted for the excellence of their telescopes, as Viviani, 
Severino, and Campani. 

1 For convenience in drawing the breadth of the telescope is 
enlarged out of proportion to its length. 


and also that (as explained above) these rays, 
passing down the tube of the telescope, are not 
allowed to come to a focus, but are intercepted by 
the eye-glass. In these respects Kepler's system 
is different ; and for work at the present day, 
although the interval of nearly three centuries has 
produced refinements and complications in the 
manufacture undreamt of by either Galileo or 
Kepler, the modern instrument is essentially a 
development of the combination devised by 
Kepler. Galileo's arrangement is suitable for low 
magnifying powers, and has advantages where 
portability is desired ; it survives in the common 
field-glass and opera-glass. 

It must further be pointed out before forming 
an estimate of Galileo's work that he knew nothing 
of the reflecting telescope. Finding, as he did, that 
a convex-lens as object-glass brought the rays of 
light from a distant object to or, more truly in 
his case, towards a focus, it seems not to have 
occurred to him that a concave mirror might serve 
the same purpose. The first reflector was designed 
by James Gregory, a Scotch mathematician, in 
1663, and described in his "Optica Promota"; but 
poverty prevented its construction. It was nine 
years later that Sir Isaac Newton, acting on 
Gregory's suggestions, and influenced also by the 
results of his own researches in the theory of light 
produced the first reflecting telescope, now pre- 
served in the rooms of the Royal Society, London. 
At the present day only a comparatively small 
number of the world's great telescopes are con- 
structed on the reflective system. But for certain 


departments of astronomical work these have 
advantages over the refractor. 1 

During the Easter recess in Padua, April 
1610, Galileo, according to custom, would probably 
have visited Florence ; but this time he had an 
express invitation from the Court, then at Pisa, to 
repair thither for the purpose of explaining to the 
Grand Duke his discovery of the four satellites of 
Jupiter, which, in honour of the reigning family 
of Tuscany, he proposed to call Medicean Stars, 
after the four brothers Cosimo II., Francesco, Carlo, 
and Lorenzo de Medici. Cosimo II., who all his 
life showed a sincere attachment to his old tutor, 
asked for and obtained the gift of the instrument 
with which this discovery was made ; 1 but Galileo 
quickly repented of his generosity. He evidently 
could not part with his "old discoverer," as he 
affectionately called it in after years ; so, while 
always reserving it for the Grand Duke, he kept it 
near himself till his death, when it was handed over 
to Prince Leopoldo, brother of Ferdinando II. 

Of its subsequent history little for certain is 
known. It would appear that in Galileo's last 
years the instrument was accidentally broken. 
Then, in 1675, there is a record in the inventory 
of the effects of Cardinal Leopoldo de Medici of a 
" broken object-glass with which Galileo discovered 
the four new planets"; and in 1677 another record 
of its having been set in an ivory frame, for which 

1 For much interesting information on the subject of telescopes, see 
Grant's " History of Physical Astronomy,' 3 London, 1852, chap, xx., 
and article " Telescope," in " Encycl. Brit.," Qth ed. 

1 Cosimo made him a return present, in the form of a gold chain 
and medal, as a badge of merit, worth about 400 scudi 

i6io] GALILEO'S "OLD D I S CO VE RE R" 97 

one Vittorio Crosterr, an engraver and carver, was 
paid 19^- lire. It is now preserved (together with 
two telescopes, said to have been made by Galileo, 
and certainly of his time) in the Tribuna di Galileo 
in Florence, with many other precious relics of the 
period. Accurate measurements of it have been 
quite recently made by Professor Roiti of the Uni- 
versity of Florence, as follows : Focal distance, 
1.70 metres; diameter .056 metre. One face has 
the curvature of a sphere with radius of .935 mtre, 
and the other face is practically plane, having just 
a trace of convexity. 




THE hundred and more telescopes, which Galileo 
had made in the first half of 1610, were distributed 
with copies of the "Sidereus Nuncius" amongst 
the princes and learned men of Italy, France, 
Flanders, and Germany. The best instruments 
he reserved for particular friends and patrons, 
amongst whom he mentions the Duke of Bavaria, 
the Elector of Cologne, Cardinal del Monte, and 
the Duke of Urbino, as having " begged" for them. 
The Cardinal sent in return a small picture to 
which an indulgence was attached ! The Duke of 
Bavaria was not behind-hand, but what his present 
was is not stated (let us hope it was more sub- 
stantial than the Cardinal's) ; while the Elector of 
Cologne wrote that the pamphlet was disappoint- 
ingly incomplete, since it contained no directions 
for the making of the instrument. He therefore 
requested Galileo to impart the secret, promising 
to recompense him in a princely fashion. 

In communicating this request, and evidently 
not caring to bear the brunt of the Elector's anger 


in case of non-compliance, Galileo's brother, Michel- 
angelo, wrote, 1 4th April 1610: 

" See if you can gratify the Elector by showing 
him how to make the instrument, and if not, write 
to him direct in your own way." 

Then he peevishly continues : 

"You say not a word about the telescope / 
asked you for. If I am not a prince, able to 
remunerate you, at least I am your brother, and it 
seems very strange to me that you do not care to 
gratify me/' 

At the French Court the arrival of Galileo's 
telescope caused immense excitement, the queen, 
Marie de Medici, being particularly interested in 
it as the invention of a distinguished fellow-country- 
man. It is related that in her eagerness to see the 
moon through it, she would not wait till the in- 
strument was suitably fixed at the open window, 
but fell on her knees on the floor, to the con- 
sternation of her suite and the amazement of the 
grave Italian in charge of the telescope. 

The solicitude of the French Court to gain a 
place in the heavens by the side of the Medici 
family is very amusing. In a letter of 2Oth April 
1610, the great astronomer is begged: 

"In case you discover any other fine star, call 
it by the name of the Great Star of France, as well 
as the most brilliant of all the earth, and, if it 
seems fit to you, call it rather by his proper name, 
Henri, than by the family name Bourbon. Thus 
you will have an opportunity of doing a thing 
due and proper in itself, and, at the same time, 

ioo PROFESSOR IN PADUA [, 592 . 

of rendering yourself and your family rich and 
powerful for ever." 1 

As the news of Galileo's marvellous discoveries 
spread over Italy, the popular excitement grew 
intense. Thus, in Florence, poets chanted the 
discoveries and the glory of their fellow-citizen, 
and a public f&te was celebrated in his honour. 
In Venice, Girolamo Sirturo describes the excite- 
ment as amounting to frenzy, and tells an amusing 
story of his own experience. With the first tele- 
scope which he had succeeded in making, he 
ascended the tower of San Marco, in the hope of 
trying it unmolested. Unluckily for him, he was 
seen by some idlers in the square below, a crowd 
soon collected round him, who insisted on taking 
possession of the instrument, and, handing it one to 
another, detained him for hours till their curiosity 
was satisfied. Desirous of obtaining the same 
gratification for their friends, they endeavoured to 
find out where Sirturo lodged, but he, overhearing 
their enquiries, thought it better to quit Venice 
early the next morning and pursue his observations 
in a less inquisitive neighbourhood. 

In the "Sidereus Nuncius" Galileo did not 
formally proclaim his discoveries in relation to, and 
in support of, the Copernican theory of the world ; 
but in his lectures and conversations he made 
no secret of his belief. Nor, indeed, was any 
specific announcement needed ; his readers could 
see for themselves the connection, .and the speedy 
result was a tremendous explosion of incredulity 
and malice. The Aristotelians were furious, and 

1 Henry IV. was assassinated very soon after, on I4th May 1610. 


even men like Welser of Augsburg, and Clavio of 
Rome, both admirers of Galileo, would not credit 
his statements until they had learnt better from 
observations of their own. The latter, who was 
the first mathematician of his day, for months, 
down to October 1610, " laughed at the idea of 
there being four new planets, to see which they 
must first be put inside the telescope. Let Galileo 
keep his opinions and welcome. I hold to mine. 51 
Nor did it mend matters when Galileo offered 
10,000 scudi to any one who would construct so 
cunning an instrument. Others refused even 
to look through the telescope; some, lest they 
should see, others convinced they could not 
see, things of which Aristotle had made no 
mention ! 

Among other sticklers for conservatism were the 
celebrated professors, Cesare Cremonino of Padua, 
one of Galileo's colleagues, and Julius Libri of Pisa, 
both of whom peremptorily rejected, on a priori 
grounds, Galileo's discoveries and the conclusions 
he drew from them. Libri died in December 1610, 
refusing to look through a telescope, and stigmatis- 
ing to the last the " absurdities " of the presump- 
tuous Florentine. In communicating the news of 
Libri's death to his friend Welser (i;th December), 
Galileo expressed the hope that this stiff-necked 
opponent of his " absurdities," who would not look 
at them from earth, might now perhaps see them 
on his way to heaven. 

Some passages of Galileo's letter to Kepler of 
1 9th August 1610 will best show how these men 
of science refused to be convinced. 


" You are the first and almost the only person, 
who, after a cursory investigation, has given entire 
credit to my statements. . . . We will not trouble 
ourselves about the abuse of the multitude, for 
against Jupiter even giants, to say nothing of pig- 
mies, fight in vain. Let Jupiter stand in the 
heavens and let the sycophants bark at him as they 
will. ... In Pisa, Florence, Bologna, Venice and 
Padua, many have seen the planets, but all are 
silent on the subject and undecided ; for the greater 
number recognise neither Jupiter nor Mars, and 
scarcely the moon, as a planet . . . What is 
to be done? Shall we side with Democritus or 
Heraclitus ? I think, my Kepler, we will laugh at 
the extraordinary stupidity of the multitude. What 
do you say of the leading philosophers here to 
whom I have offered a thousand times of my own 
accord to show my studies, but who, with the lazy 
obstinacy of a serpent who has eaten his fill, have 
never consented to look at the planets, or moon, or 
telescope ? Verily, just as serpents close their ears, 
so do men close their eyes to the light of truth. To 
such people philosophy is a kind of book, like the 
^Eneid or the Odyssey, where the truth is to be 
sought, not in the universe or in nature, but (I 
use their own words) by comparing texts ! How 
you would laugh if you heard what things the first 
philosopher of the faculty at Pisa brought against 
me in the presence of the Grand Duke. He tried 
hard with logical arguments, as if with magical in- 
cantations, to tear down and argue the new planets 
out of heaven ! l 

As a specimen of the " logical " arguments to 
which Galileo alludes in the above extract, this is 

1 Ponsard in his drama " Galilee," Paris, 1867, takes off capitally 
these proud Aristotelians (Act I. Scenes 3 and 4) ; but in the process 
Galileo's history is mostly turned upside down. 


what Francesco Sizzi, a Florentine astronomer, says 
in his " Dianoia Astronomica" (Venice, 1611.) 

''There are seven windows given to animals 
in the domicile of the head, through which the 
air is admitted to the tabernacle of the body, to 
enlighten, to warm, and to nourish it. What 
are these parts of the microcosmos? Two nostrils, 
two eyes, two ears, and a mouth. So in the 
heavens, as in a macrocosmos, there are two 
favourable stars, two unpropitious, two luminaries, 
and Mercury undecided and indifferent. From 
this and many other similarities in nature, such 
as the seven metals, etc., which it were tedious 
to enumerate, we gather that the number of 
planets is necessarily seven. Moreover, these 
satellites of Jupiter are invisible to the naked 
eye, and therefore can exercise no influence on 
the earth, and therefore would be useless, and 
therefore do not exist. Besides, the Jews and 
other ancient nations, as well as modern 
Europeans, have adopted the division of the 
week into seven days, and have named them 
after the seven planets. Now, if we increase 
the number of the planets, this whole and 
beautiful system falls to the ground." 1 

Another opponent deserves to be named, if 
only for the impudence of the charge he brings 
against Galileo. 

"We are not to believe/' says Christmann, 
in his " Nodus Gordius," "that nature has 
given Jupiter four satellites in order to immortalise 
the name of the Medici. These are the dreams 

1 Sizzi would not look through the telescope, because he was sure 
beforehand he could not see any of the marvels which Galileo pre- 
tended to find in the heavens by its aid. In 1618 he was broken on 
the wheel in Paris for some political crimes. 

104 PROFESSOR IN PADUA [i 592 . 

of idle men who love ludicrous ideas better 
than our laborious maintenance of the heavens. 
Nature abhors such horrible chaos, and to the 
truly wise such vanity is detestable." 

In the midst of all this opposition and abuse, 
we must not suppose that Galileo was without 
friends, and even some converts. Thus, on 7th 
May 1 6 10, he was able to inform Secretary 
Vinta that even the most exalted persons in 
Padua, who had vehemently attacked him, had 
at length given up the game, and had acknow- 
ledged, coram publico, that they were not only 
convinced, but were ready to defend him against 
all comers. 

The praises of Kepler, then renowned as 
the first astronomer in Europe, were, as we 
have just seen, a great consolation to him. 
Kepler had the " Sidereus Nuncius" at once 
reprinted in Prague, with a long and appreciative 
preface from himself, and some laudatory verses 
from Thomas Seggett, a learned Scotchman, a 
former pupil of Galileo, then working with him, 1 
In the preface, which is in the form of a letter to 
Galileo, dated iQth April 1610, Kepler says: 

" I was sitting idle at home thinking of you, 
most excellent Galileo, and of your letters, when 
the news was brought me of the discovery of 
four planets by the help of the double eye- 
glass. . . . The authority of Galileo had the 
greatest influence on me, earned by the accuracy 
of his judgment, and by the excellence of his 

1 The oft-quoted exclamation, Galilaee! vicistil is always wrongly 
attributed to Kepler. It occurs in Seggett's verses. 


understanding. So I immediately fell to thinking 
how there could be any addition to the number 
of the planets without upsetting my ' Mysterium 
Cosmographicum," published thirteen years ago, 
and according to which Euclid's five regular 
solids do not allow more than six planets round 
the sun. I am, however, so far from disbelieving 
the existence of the four circumjovial planets, 
that I long for a telescope to anticipate you, if 
possible, in discovering two round Mars (as the 
proportion seems to require), six or eight round 
Saturn, and, perhaps, one each round Venus and 
Mercury." 1 

Galileo's detractors must have been hard 
pushed for a stick wherewith to strike him when 
they took Kepler's preface to be a covert attack. 
Certainly Maestlin, Kepler's old master, took it 
so, and wrote : 

" In your essay you have plucked Galileo's 
feathers well I mean you have shown him not 
to be the inventor of the telescope, not to be 
the first to observe the irregularities of the moon's 
surface, not to be the first discoverer of more 
worlds than the ancients were acquainted with, 
etc. One source of exultation was still left him, 
but from the apprehension of that Martin Horky 
has now entirely delivered me." 

1 This is a specimen of the wild notions in which Kepler 
revelled. For the same curious reason Huygens, who in 1659 
discovered a satellite near Saturn, declared that no more would 
be found, since the one near Saturn, Jupiter's four, and the earth's 
one, made up the number six, exactly the number of the planets, thus 
together making twelve, which is the first perfect number 1 In 
Galileo's day Scheiner thought he saw five satellites round Jupiter, 
de Rheita counted nine, and others gave him a round dozen! 
Jupiter is now known to have five, Saturn eight, besides his rings, 
Uranus four, Ne tune one, and Mars two. 


It is difficult to see where in Kepler's preface 
Maestlin found all this, for it is one continued 
encomium. Maestlin, however, was not the only 
one to misunderstand. The Martin Horky just 
mentioned, a young German travelling in Italy, 
wrote to Kepler: 

" I will never concede his four new planets 
to that Italian from Padua, though I die for 

He followed up this declaration by publishing 
a book, which is evidently the one referred to by 
Maestlin. 1 It professes to examine four main 
questions touching the alleged planets (i) 
Whether they exist? (2) What are they? (3) 
What are they like ? (4) Why they are ? Horky 
summarily disposes of the first question by 
declaring that he had examined the heavens with 
Galileo's own glass, and could see no such thing as 
a satellite about Jupiter. As to the second he 
declares solemnly that he does not more surely 
know that he has a soul in his body, than that 
reflected rays are the sole cause of Galileo's 
observations. In regard to the third question he 
says, rather illogically, that these planets are like 
the smallest fly compared with an elephant ; and as 

1 " Peregrinatio contra Nuncium Sidereum^ Galileo, by the advice 
of Kepler, did not deign to reply, but he found able champions in his 
Scotch friend and pupil, John Wedderburn of Padua (p. 51), and in 
Antonio Roffeni v a professor in the University of Bologna. Apparently, 
our old acquaintance, Professor Magini, was the secret instigator of this 
outrage, but, openly, he pretended to be very shocked at Horky's bad 
manners. The latter, however, afterwards confessed to Kepler that 
Magini and other professors in Bologna were the real offenders. Sizzi 
had admitted the same inspiration in the case of his " Dianoia Astro- 
nomica," of which we have already spoken. 


to the fourth he concludes that the only use of them 
is to gratify Galileo's vanity and thirst of gold. 
Horky sent a copy of this amazing production to 
Kepler, and, returning to Prague soon after, 
presented himself to the great astronomer. But 
the reception was little to his taste, for the burst of 
indignation which followed showed him Kepler's 
real sentiments. The conclusion is characteristic. 
After venting his wrath against "this scum of a 
fellow, whose obscurity had given him audacity," 
Kepler, recounting the story to Galileo, says : 

" In the end, Horky begged so hard to be 
forgiven that I have taken him again into favour 
upon this one condition, to which he has agreed 
that I am to show him Jupiter's satellites, and that 
he is to see them, and own they are there." 1 

After completing his observations on Jupiter, 
Galileo turned his glass to the other planets to see 
if they, perchance, had attendant moons ; but up 
to 25th June 1610, he was unable, with all his 
diligence, to discover any. At this he was inclined 
to be a little glad and a little sorry glad because 
he would thus be the only one destined by God for 

1 See Kepler's letter to Galileo, dated 25th October 1610. As 
usual, Galileo's right to the first discovery of Jupiter's satellites was 
contested, the claimant being Simon Mayer of Anspach, whom we 
have met before in connection with the Capra plagiary (p. 45 ante]. 
In 1614 he published at Nuremberg his "Mundus Jovialis," in which 
he formulates his claims. As to these, it is enough to say with 
Humboldt that Kepler, who knew Mayer personally, makes no mention 
of his discovery either in the edition of the " Sidereus Nuncius " which 
he published in Prague in April 1610, or in his letters to Galileo, 
or in those addressed to the Emperor, Rudolph II., in the autumn 
of 1610. On the contrary, Kepler always spoke of "the glorious 
discovery of the Medicean stars by Galileo." See " Cosmos," vol. ii. 
p. 70S- 


so great a discovery ; and sorry because he could 
not oblige the French Court by finding Henri 
Quatre a place in the heavens. However, before 
a month elapsed, he made another brilliant 
discovery the ring of Saturn ; only it did not 
appear to him as a ring, but like a triple star, of 
which the central one (Saturn itself) was three to 
four times larger than the laterals, and all three in 
a plane parallel to the equinoctial points or ecliptic. 
Not wishing to make public the discovery until he 
had made further observations in the autumn, when 
Saturn would be well above the horizon, and yet 
fearing that some one might forestall him, he 
announced the discovery in a brief letter, dated 
Padua, 3Oth July 1610, to Belisario Vinta at 
Florence, but begged him to keep it secret for 
a while. As a further precaution he sent to friends 
in Italy and Germany a jumble of thirty-seven 
letters as follows : 


Kepler and other friends puzzled long over 
this string of letters, the former thinking it had 
some reference to his favourite planet Mars. At 
length Giuliano de Medici, Tuscan ambassador 
at the German Court, was charged by the Emperor 
Rudolph IL to ask for the solution, to whom 
Galileo, replying i3th November 1610, gave the 
following startling explanation : 

" Altissimum Planetam Tergeminum Observavi." 

"I have observed," he goes on to say, "with 
great admiration that Saturn is not a single star 

i6xo] SATURN'S RING 109 

but three together, which, as it were, touch each 
other. They have no relative motion, and 
are constituted in this form (see Fig. 8, A), the 
middle being much larger than the lateral ones. 
If we examine them with a glass of inferior 
power, the three stars do not appear very 

Fig. 8. 

(Facsimiles from Galileo's 

(A) (B) (C) 


distinctly. Saturn has an oblong appearance 
somewhat like an olive, but by employing a glass 
which multiplies the superficies more than 1000 
times, the three globes will be seen very distinctly 
and almost touching, with only a small dark space 
between them. 1 

" I have already discovered a court for Jupiter, 
and now there are two attendants for this old man, 
who aid his steps and never leave his side." 

The learned world of Italy had not yet had 
time to digest the surprising facts announced in 

1 The telescope with which Galileo discovered Jupiter's satellites 
had, as we have seen, a power of 30, enlarging objects "nearly 
loco times." Here, and in other letters of the latter half of 1610, 
he speaks of his glass enlarging " more than 1000 times," but without 
specifying the power, as in all previous cases. From this, Professor 
Favaro concludes that between April and July Galileo had made for 
himself a sixth telescope. This may be so, but I think it more likely 
that he only improved his fifth, his "old discoverer" (for instance, by 
substituting a better eye-glass), thereby increasing its enlarging 
power from nearly 1000 to more than 1000. Indeed, in his letter to 
Clavio of 1 7th September 1610, he says as much " Having 
ultimately improved my instrument a little more." Galileo never got 
beyond this power. 


the "Sidereus Nuncius," when the asserted triple 
nature of Saturn again contravened the prevail- 
ing ideas that, by order of Aristotle, there was 
nothing new to be found in the heavens. Accord- 
ingly, the peripatetics were inclined to discredit 
the discovery ; the most they would admit was 
that Saturn appeared to be of an oblong shape 
precisely as Galileo said it appeared when viewed 
through glasses of less power than his own. 

Continuing his observations, Galileo found that 
the lateral bodies did not retain the same ap- 
parent magnitudes. In fact, they had been gradu- 
ally diminishing, although they appeared to be 
immovable, both with respect to each other and 
to the central body. They continued to grow less 
and less during the next two years, and towards 
the close of 1612 they vanished altogether! Horri- 
fied at this extraordinary phenomenon, and full of 
alarm for the consequences to himself when his 
Aristotelian opponents should come to hear of 
it, he thus wrote to Welser on ist December 
1612 : 

" Looking at Saturn within these last few 
days, I found it solitary without its accustomed 
stars, and, in short, perfectly round and defined 
like Jupiter, and such it still remains ! Now what 
can be said of so strange a metamorphosis ? Are, 
perhaps, the two smaller stars consumed like spots 
on the sun? Have they suddenly vanished and 
fled? Or has Saturn devoured his own children? 
Or was the appearance, indeed, fraud and illusion, 
with which the glasses have for so long mocked 
me and many others who have observed with 
me? Now, perhaps, the time is come to revive 

i6io] SATURN'S RING in 

the withering hopes of those who, guided by more 
profound contemplation, have fathomed all the 
fallacies of the new observations, and recognised 
their impossibility. I cannot resolve what to say 
in a change so strange, so new, so unexpected. 
The shortness of time, the unexampled occur- 
rence, the weakness of my intellect, the terror of 
being mistaken, have greatly confounded me." 1 

However, he soon plucked up courage, and in 
the same letter conjectured that the two attendant 
stars would reappear after revolving round the 
planet, and that by the summer solstice of 1615, 
they would not only be again visible, but be 
more luminous, and larger. 

Commenting on the above quoted passage, 
Arago 2 and other modern writers after him con- 
clude that Galileo was so discouraged by the 
disappearance of the lateral bodies that he made 
no further observations on Saturn. But Arago 
is most certainly wrong here. Galileo continued 
to observe Saturn for many years. By the middle 
of 1613, he was able to inform his friends that, 
according to his prediction, the lateral stars were 
reappearing ! 

Apparently, no change calling for special com- 
ment was noticeable until the summer of 1616, 

1 The real reason is now well known. The ring lies in the plane 
of Saturn's equator, and we obtain a view of its north or south side 
according as the planet at different -parts of his orbit leans his north 
pole towards or away from the earth. Accordingly the ring goes 
through all its phases once during the twenty-eight years of Saturn's 
revolution round the sun ; disappearing twice in that period, at the 
time when the planet is so placed that he presents the ring edgeways 
to our line of vision. 

8 "Astronomic Populaire," Paris, 1857, vol. iv. p. 442. 


when he announced a new fact relating to 
Saturn, which filled his friends with admiration 
and pleasure. For considerably more than two 
hundred years this new fact remained not only 
unexplained, but forgotten. Then Alberi, while 
preparing his edition of Galileo's Works, 1842-56, 
found amongst his MSS. a paper containing some 
calculations belonging to the year 1616, on the 
back of which was a pen-and-ink sketch, as shown 
in Fig. 8, b}. No explanation of the figure was 
to be found, but Alberi concluded that it was 
intended to show the form of Saturn's ring as 
seen by Galileo in August 1616, and as com- 
municated to his friends, as above stated. 

Not satisfied with the evidence that the sketch 
found by Alberi was really made by Galileo, and 
that it belonged to the date assigned, Professor 
Favaro has lately instituted a new search, and 
with the happiest results. Taking as his starting- 
point a letter from Prince Cesi to Galileo of 3rd 
September 1616, acknowledging the "new fact" 
about Saturn, 1 Favaro has been rewarded by 
finding the ipsissima verba of Galileo. They 
were sent by Prince Cesi to John Faber in 
Rome for his information, and by him immediately 
passed on, as the latest piece of news, to Cardinal 
Federigo Borromeo, amongst whose papers, now 
in the Ambrosian Library, Milan, Favaro found 
them. Quite recently the learned Professor has 
read a paper on this interesting discovery, from 
which I quote Galileo's words as follows : 

1 Unfortunately, the year 1616 is one of those in which Galileo's 
correspondence, as it has come down to us, is incomplete. 

i6io] SATURN'S RING 113 

" I cannot rest without signifying to your Ex- 
cellency [Prince Cesi] a new and most strange 
phenomenon observed by me in the last few 
days in Saturn. Its two companions are no 
longer two small and perfectly round globes, as 
they have hitherto appeared to be, but are now 
bodies much larger, and of a form no longer 
round, but, as shown in the annexed figure (see 
Fig. 8, c), with the two middle parts obscured, 
that is to say, two very dark triangular-like spaces 
in the middle of the figure and contiguous to the 
middle of Saturn's globe, which latter is seen, 
as always, perfectly round." 1 

Towards the end of his life, when Galileo was 
blind, and a confirmed invalid from age and ail- 
ments, he once more referred to Saturn. Cas- 
telli, writing to him from Rome under date 4th 
August 1640, said : 

" The other evening, on turning the telescope 
towards Saturn, I noticed, to my great amaze- 
ment, that he was a single star, distinct and 
round, and with two other round stars (one at 
each side) lying in the direction from Levante 
to Ponente [i.e. nearly east and west], and no 
longer in the form of coifs attached to the 
central body, such as your first observations 
showed them." 

Replying on 28th August 1640, Galileo wrote : 

" When first I observed Saturn he was com- 
posed of three round stars, situated in a straight 
line from Ponente to Levante, of which the 
central was much larger than the lateral ones. 
Thus I continued to see him for some months. 

1 Atti del Real* Istituto Veneto^ February, 1901. 

ii4 PROFESSOR IN PADUA [i 592 - 

Then, after an interval of some more months, 
I again examined him and found him solitary, 
z>. the great central star was only to be seen. 
Amazed at this result, and supposing it to be 
due to some kind of change, I ventured to say 
that in five or six months, i.e. at the summer 
solstice, the two small lateral stars would reap- 
pear. They did, and so I saw them for a long 
time after. Then after another interval, during 
which Saturn was masked by the sun's rays, I 
again observed him, and now saw him with two 
mitres, instead of round stars, which gave him 
the figure of an olive. I saw the central globe 
very distinctly, and two very dark spots in the 
middle of the attachment of the mitres, or, as 
one may say, the ears. So I observed him for 
many years ; and now your Rev, writes (as also 
other of my friends) that the mitres are trans- 
formed into two small globes. It may be that 
in the last three years, during which I have 
been unable to make any observations, 1 Saturn 
may have become once again solitary, and then 
later on may have returned to the form in which 
I at first observed him. It will be for the future 
and for others to make observations, registering 
the times of mutation so as to accurately de- 
termine their periods that is, if there will 
be any persons curious enough to do what I, 
from the same motive (not knowing how to do 
better), have done for so long a time." 

Thus we see that up to the last, Galileo had 
made no announcement as to the precise nature 
of Saturn's appendage. He contented himself 
with describing what he saw, and, recognising the 
incompleteness of his knowledge, and, perhaps, 

1 Galileo became totally blind in December 1637, 


the inadequate power of his glasses, he left it 
to the future and to others to solve the problem. 
This was done by Christian Huygens in 1656. 
Working with a refracting telescope with a magni- 
fying power of 100 diameters, this celebrated 
astronomer not only saw and described the ring 
as a ring, but discovered one of Saturn's satellites, 
of which eight are now known to exist. 





GALILEO'S fame, especially through his telescopic 
discoveries, and partly also through the exertions 
of his noisy opponents, had long extended beyond 
the bounds of Italy. The eyes of all Europe 
were directed to the great astronomer of Padua, 
and students flocked to him from all quarters. 
According to a familiar French proverb, one 
must suffer in order to be beautiful, so, to be a 
professor with a European reputation demands 
some sacrifice, entails some evil, which, under 
certain circumstances, may outweigh the good. 
It was so in Galileo's case ; lectures and private 
lessons of all kinds left him little leisure for his 
own studies, and so, after twenty years' professor- 
ship at Pisa and Padua, he began to wish for a 
post in which he could devote himself entirely to 
the completion of various works on mechanics and 
astronomy, for which, during all these years, he 
had been amassing materials. A letter from Padua 
in the spring of 1609, shows his longing for this 
salaried leisure. It is not addressed, but from the 

context it must have been written to some one 


high in influence, if not in office, at the Court of 
Florence, probably to Belisario Vinta, the Grand 
Duke's chief Secretary of State. 1 This first 
attempt, however, had no definite result, so that 
a few months later (after the invention of the 
telescope) he gratefully accepted, as we saw, the 
Chair of Mathematics at Padua for life. But the 
invention of the telescope and his consequent dis- 
coveries had now given him a world-wide reputa- 
tion, and it appeared desirable to the Tuscan 
Court to attach to itself so great a man. 

The first steps towards this end were taken 
when Galileo visited Pisa, about Easter 1610, in 
order to show to Cosimo II. his telescopic dis- 
coveries, and especially the satellites of Jupiter, 
which bore his family name of Medici. Galileo's 
case is fully stated in his letter of 7th May 1610, 
to Vinta, as follows : 

" I will not hesitate to say, having now laboured 
during twenty years, and those the best of my life, 
in dealing out (as one may say) in detail, and at 
the request of everybody, the little talent which 
God has given me, that my wish is to have 
sufficient leisure to enable me, before my life 
comes to a close, to conclude three great works 
which I have in hand, and which may, perhaps, 
bring some credit to me and to those who assist 
me in the undertaking, besides being a greater 
service to students than in the rest of my life I 
could do them by personal tuition. Greater leisure 
than I have here I doubt if I could get elsewhere, 
so long as I am obliged to give public and private 
lectures in order to meet the expenses of my family. 

1 We do not reproduce it, as its substance is given in a later and 
fuller communication quoted infra. 


Nevertheless, not even the liberty I have here is 
sufficient, when I am obliged to spend many and 
often the best hours of the day at the call of this 
and that man. My salary is 520 florins, which I 
am almost certain will be advanced to as many 
crowns upon my re-election, and this I can increase, 
by receiving pupils and by private lessons, to any 
extent I please. My public duties do not occupy 
me more than sixty half-hours in the year, and 
even then not so strictly but that I may, on 
occasion of any pressing matter, contrive to get 
some vacant days. The rest of the time is 
absolutely at my own disposal ; but as my private 
lectures and domestic pupils take up very much 
of this spare time, to the hindrance of my own 
studies, I wish to be entirely exempt from public 
duties, and in a great measure from the others. 
Therefore, if I am to return to my native country, 
I should wish that leisure and opportunity be 
afforded me to complete my works without em- 
ploying myself in lecturing. In short, I wish to 
gain my bread by my writings, which I would 
always dedicate to my Serene Master. 

" Of useful and curious secrets I possess so 
many that their very abundance does me harm, 
for if I had but one I should esteem it greatly, 
and, perhaps, through it I might have found that 
fortune which as yet I have not met. And, 
indeed, I have not sought it. Magna longeque 
admirabilia apud me habeo. Many are no good 
to me, or I should say, they are only of use to 
princes ; for they alone make wars, build fortresses, 
and, for their royal pleasure, spend such sums of 
money as private gentlemen cannot, any more than 
I can. 

"The works which I have to finish are chiefly 
(i) two books on the system or structure of the 
Universe, an immense work, full of philosophy, 


astronomy, and geometry; (2) three books on 
local motion, a science entirely new, no one, 
ancient or modern, having discovered any of the 
many admirable consequences which I demonstrate 
in natural and violent motions, so that I may with 
reason call it a new science invented by me from 
its very first principles ; (3) three books on 
mechanics, two on the demonstration of principles, 
and one of problems. Although others have 
treated this subject, no one either in quantity or 
quality has done a quarter of what I am writing 
on it. I have also treatises on natural and other 
subjects, such as (i) on sound and speech; (2) on 
light and colours; (3) on the tides; 4) on the 
composition of continuous quantity ; (5) on the 
movements of animals ; and others. I have also an 
idea of writing some books relating to the military 
art, giving not only a model of what a soldier 
ought to be, but teaching him with exact rules 
everything in the way of mathematics that it is 
his duty to know, as castrametation, manoeuvring 
battalions, fortifications, sieges, surveying, estima- 
tion of distances, knowledge of artillery, uses of 
various instruments, etc. 

" I also wish to reprint the 'Use of the Geo- 
metrical and Military Compass/ which is dedicated 
to his Highness, and is no longer to be procured. 
This instrument has met with such favour from 
the public that no others of the kind are now 
made, and I know that up to this several thousands 
of mine have been made and sold. 

" Then I need not say what an amount of 
labour will be required to fix the periods of the 
four new planets, a task the more laborious the 
more one thinks of it, as they are separated from 
one another by very brief intervals, and are all 
very similar in size and colour. So that, illustrious 
Signor, I must begin to think in what way I can 


free myself from those employments which so retard 
my own studies particularly those, which another 
might fill quite as well as I can. Therefore, I beg 
you to bring these considerations to the notice of 
his Highness, and acquaint me with his decision. 

"As to salary, I shall be quite content with 
the sum you named to me at Pisa, feeling it an 
honour to be his Highness s servant. I say 
nothing as to the amount, being convinced that as 
I am to live upon it his Highness would not 
wish to deprive me of any of those comforts which 
others enjoy, who are less in want of them than 
I am. Therefore I say no more on this point. 

" Finally, as to the title and pretext by which 
I take service, I would wish that to the title of 
Mathematician his Highness would be pleased to 
add that of Philosopher, as I have studied a greater 
number of years in philosophy than months in pure 
mathematics. And how far I have profited by it, 
and if I can and ought to merit the title, I hope 
to be able to show his Highness as often as it is 
his pleasure to give me an opportunity of discuss- 
ing such subjects with those whose knowledge is 
most esteemed." l 

1 Some of the treatises named in this letter, like the one on 
dialling previously mentioned, and, it is feared, more of Galileo's 
papers and correspondence, are now lost, partly through the accidents 
of his stormy life, and in transport from place to place, and partly, 
as we shall see later on, through the extraordinary negligence and 
criminality of custodians. The loss of the essay on Continuous 
Quantity is particularly to be regretted, as it would be interesting to 
see how far he succeeded in methodising his thoughts on this im- 
portant subject. It is to his early disciple Buonaventura Cavalieri 
(who refused to publish his book so long as he hoped to see Galileo's 
printed) that we owe " The Method of Indivisibles," which is recog- 
nised as one of the first germs of Newton's Fluxional Calculus. The 
treatises on sound and speech and on light and colours were probably 
never completed, but we find fragments of them in later works, as "II 
Saggiatore" and the Dialogues of 1632 and 1638. Similarly, of the 
movements of animals we have the fragment " Intorno al camminare 
del cavallo." 


This letter brought the business to a speedy 
settlement. On 5th June, Vinta wrote that 
Cosimo II. was pleased to nominate him as First 
Mathematician of the University of Pisa, with 
a yearly salary of 1000 scudi, and without the 
obligation of residing at Pisa, or of delivering 
lectures. In reply, Galileo declared himself en- 
tirely satisfied with the proposed conditions, but 
added that he would like to be designated not 
only First Mathematician at Pisa, but also Philo- 
sopher and Mathematician to the Grand Duke 
himself. Accordingly, on i2th July 1610, the 
decree summoning him to Florence in this two- 
fold capacity was issued. 

Notwithstanding the many advantages which 
this new post secured to him, it was a bad ex- 
change from the free soil of Republican Venice to 
the protection (ineffectual as it proved at the crisis 
of his life) of a princely house which, although 
personally well disposed towards him, could never 
shield him as could and would the Republic. 
About 1542, the Jesuits had established a school 
in Padua, and, increasing gradually in influence, 
had shown symptoms of a design to get the 
management of public education entirely into their 
own hands. After several violent disputes, it 
was at length decreed by the Venetian Senate, 
in 1591, that no Jesuit should be allowed to give 
instruction at Padua in any of the sciences taught in 
the University. As years dragged on, the relations 
between Rome and Venice became increas- 
ingly strained, until at last, in April 1606, Pope 
Paul V, took the extreme step of placing the 


contumacious Republic under an interdict. The 
Senate's reply was to expel for ever the Jesuits 
from the soil of Venice. 1 Since this event, full 
liberty of thought and teaching was enjoyed in the 
Republic ; whereas, in religious Tuscany, Church 
influences were very strong and weighed heavily in 
all matters, and particularly in politics and science. 

Early in September 1610, Galileo left Padua, 
where, eighteen years before, he had found ^ a 
ready welcome and an ever-increasing apprecia- 
tion, deserting his staunch friends Paolo Sarpi, 
Francesco Sagredo, and many others. Indeed, 
he seems to have felt himself that he was not 
behaving well in this matter, for, in his letter to 
Vinta last quoted, he begged that the negotia- 
tions be kept secret until all was decided and 
therefore irrevocable. 2 

Although he was received in Florence with 
much honour, soon the clouds of envy, malice, 
and bigotry, began to form round him, and ulti- 
mately, as we shall see, combined, if not to his 
destruction, at least to embitter the rest of his 
life. Sagredo foresaw this clearly. On his re- 
turn from the East in the spring of 1611, he 
wrote expressing his regret and disappointment 
at not finding Galileo, and his grave doubts as 
to the wisdom of the change. 

1 Their nocturnal deportation from the city of lagoons is amusingly 
told in Galileo's letter of nth May 1606, to his brother Michelangelo. 

2 Galileo tried to induce Kepler to apply for his chair in Padua, 
but without success. Again in 1617, on the death of Magini, Kepler 
was offered the vacant chair in Bologna, which he once more refused. 
See Martin's "Galile'e," Paris, 1868, pp. 14 and 194; and for Kepler's 
reasons, Drinkwater's " Life of Kepler," in Library of Useful Know- 
ledge, p. 38. 


" Where," he asks, "will you find the same 
liberty as in Venetian territory, and, notwith- 
standing all the good qualities of the young ruler 
of Tuscany, who can promise with any confidence 
that, if not ruined, you will not be persecuted and 
tossed on the surging billows of Court life by the 
raging storms of envy?" 

Within less than a month after his arrival in 
Florence, Galileo made another astounding dis- 
covery in the heavens namely, the varying 
crescent form of the planet Venus. He announced 
this discovery to his correspondent, Giuliano de 
Medici at Prague, in an anagram, as in the case 
of his observations on Saturn, as follows : 

"Haec immatura a me iam frustra leguntur o y" 

and after convincing himself, by three months' 
observations, of its correctness, he sent the follow- 
ing solution of the riddle on ist January 1611. 

" Cynthiae figuras aemulatur mater amorum" 

"That is, Venus rivals the appearances of the 
moon ; for Venus being now arrived at that part 
of her orbit in which she is between the earth 
and the sun, and with only a part of her en- 
lightened surface turned towards us, the telescope 
shows her in a crescent form, like the moon in a 
similar position." 

Tracing her through the visible portion of 
her orbit, Galileo had the satisfaction of seeing 
the illuminated part assume successively the forms 
appropriate to his hypothesis. It was with reason, 
therefore, that he laid stress on the importance of 
this observation, which established yet another 


fact obnoxious to the Aristotelians, namely, that 
a new point of resemblance was here found 
between the moon and one of the principal 
planets ; for, as it was well known that the moon 
was luminous only when exposed to the sun's 
rays, so this change of figure in Venus demon- 
strated that she, and, therefore, probably all the 
other planets, were of themselves not luminous, 
but only reflected the sunlight which fell upon 
them. And thence he concluded that they must 
all revolve round the sun "a fact which was 
surmised by Pythagoras, Copernicus, Kepler, and 
their disciples, but which could not be proved by 
ocular demonstration, as it now can be in the case 
of Venus and Mercury. Kepler and the other 
Copernicans may now be proud to have judged 
and philosophised correctly, and it may well excite 
disgust that they were regarded by the generality 
of men of book-learning as having little under- 
standing and as not much better than fools.'* 

It had always been a formidable objection to 
the Copernican theory that Venus and Mercury 
did not exhibit the same phases as the Moon, 
which they should do if they revolved round the 
sun. Copernicus himself had endeavoured to 
account for this, by supposing that the sun's rays 
passed freely through the body of the planets, and 
Galileo took occasion to praise him for not being 
deterred from adopting the system (which on the 
whole appeared to agree best with the phenomena) 
by meeting with some appearances which it did 
not enable him to explain. 

Another objection, equally embarrassing to the 


Ptolemaic and Copernican systems, was raised. 
Why, it was asked, did not Venus appear four 
times as large when nearest to the earth as when 
farthest away? Galileo was now able to answer 
this also. Venus does not appear four times as 
large when she is nearest to the earth, simply 
because her illuminated part is not then four 
times as large, though her diameter is ; and as 
with the naked eye we judge of her size only by 
the amount of light, the nearer distance is offset 
by the lesser light, so that her size does not 
seem to vary. 1 

Milton, whose Paradise Lost has many allusions 
to Galileo and his astronomy, has not suffered this 
brilliant discovery to pass unnoticed. After describ- 
ing the creation of the sun he adds : 

" Hither, as to their fountain other stars 
Repairing, in their golden urns draw light, 
And hence the morning planet gilds her horns." 2 

Of changes in Mars Galileo could say little for 
certain. After observing him carefully for four 
months he was seen to vary in size according to 
his distance from the sun. Galileo thought that 
when the planet was at the middle points of his 
orbit he observed changes in the illuminated disc 
something like the phases of the Moon and Venus ; 
but it is difficult, he adds, with so small an object 
to say whether it is always perfectly round. 

1 The revolution of Mercury about the Sun which Galileo here 
infers, was confirmed as a fact by Kepler's observation of the transit 
of Mercury in 1630. Our countryman, Horrox, was the first to observe 
a transit of Venus in 1639. 

a Book VII. v. 364. For other references, see Book I. v. 286; 
III. 565 et seq., 722 et seq.; IV. 589; V. 261, 414 ; VII. 577; VIII. 


fact obnoxious to the Aristotelians, namely, that 
a new point of resemblance was here found 
between the moon and one of the principal 
planets ; for, as it was well known that the moon 
was luminous only when exposed to the sun's 
rays, so this change of figure in Venus demon* 
strated that she, and, therefore, probably all the 
other planets, were of themselves not luminous, 
but only reflected the sunlight which fell upon 
them. And thence he concluded that they must 
all revolve round the sun "a fact which was 
surmised by Pythagoras, Copernicus, Kepler, and 
their disciples, but which could not be proved by 
ocular demonstration, as it now can be in the case 
of Venus and Mercury. Kepler and the other 
Copernicans may now be proud to have judged 
and philosophised correctly, and it may well excite 
disgust that they were regarded by the generality 
of men of book-learning as having little under- 
standing and as not much better than fools." 

It had always been a formidable objection to 
the Copernican theory that Venus and Mercury 
did not exhibit the same phases as the Moon, 
which they should do if they revolved round the 
sun. Copernicus himself had endeavoured to 
account for this, by supposing that the sun's rays 
passed freely through the body of the planets, and 
Galileo took occasion to praise him for not being 
deterred from adopting the system (which on the 
whole appeared to agree best with the phenomena) 
by meeting with some appearances which it did 
not enable him to explain. 

Another objection, equally embarrassing to the 


Ptolemaic and Copernican systems, was raised. 
Why, it was asked, did not Venus appear four 
times as large when nearest to the earth as when 
farthest away? Galileo was now able to answer 
this also. Venus does not appear four times as 
large when she is nearest to the earth, simply 
because her illuminated part is not then four 
times as large, though her diameter is ; and as 
with the naked eye we judge of her size only by 
the amount of light, the nearer distance is offset 
by the lesser light, so that her size does not 
seem to vary. 1 

Milton, whose Paradise Lost has many allusions 
to Galileo and his astronomy, has not suffered this 
brilliant discovery to pass unnoticed. After describ- 
ing the creation of the sun he adds : 

" Hither, as to their fountain other stars 
Repairing, in their golden urns draw light, 
And hence the morning planet gilds her horns." 2 

Of changes in Mars Galileo could say little for 
certain. After observing him carefully for four 
months he was seen to vary in size according to 
his distance from the sun. Galileo thought that 
when the planet was at the middle points of his 
orbit he observed changes in the illuminated disc 
something like the phases of the Moon and Venus; 
but it is difficult, he adds, with so small an object 
to say whether it is always perfectly round. 

1 The revolution of Mercury about the Sun which Galileo here 
infers, was confirmed as a fact by Kepler's observation of the transit 
of Mercury in 1630. Our countryman, Horrox, was the first to observe 
a transit of Venus in 1639. 

a Book VII. v. 364. For other references, see Book I. v. 286 ; 
III. 565 et seq., 722 et seq.; IV. 589*; V. 261, 4H ; VII. 577; VIIL 


Of Mercury lie also observed little, because 
that planet's orbit does not take him far from 
the sun, and, in consequence, his small disc is 
always so resplendent that not even the best 
telescope could deprive him of his factitious rays 
(irradiation). 1 

In consideration of the intense interest, friendly 
and otherwise, excited by these epoch-making 
discoveries, and the probability of their being 
used against him in Rome, Galileo thought it 
desirable to go there himself, and acquaint at 
first hand the savants and dignitaries of the 
Church with his work in the heavens. These 
people, he argued, must be first made to see the 
facts with their own eyes, so that they may be 
able to comprehend and assent to the conclusions 
to be drawn from them. Therefore, on I5th 
January 1611, he wrote to Vinta (who was then 
with the Court at Pisa), informing him of his 
design, adducing the above reasons, and request- 
ing the necessary leave of absence. His request 
was not only granted but the Grand Duke placed 
a litter at his disposal, undertook to defray all 
expenses, and directed the Tuscan Ambassador 
in Rome to lodge him at the Embassy and to 
entertain him during the visit. Illness, however, 
supervened, so that it was not till 23rd March 
1611, that he was able to set out, provided with 
many letters of introduction, amongst them one 
from Michelangelo the younger (nephew of the 

1 For Galileo's observations on Venus, Mercury, and Mars, see his 
letters to Castelli, dated soth December 1610, and to Clavio in Rome 
under the same date. 


great sculptor and painter) to Cardinal Barberini 
(afterwards Pope Urban VI I L), 

He was received with the greatest distinction 
by princes and all the Church dignitaries, who 
vied with learned laymen in doing him honour. 
Even those who discredited his discoveries and 
dreaded their results, were as eager as the true 
friends of science to see and hear this wonder of 
the age. His first duty was to call on his old 
friends, Cardinal del Monte and the Jesuit Father 
Clavio, by the latter of whom he was presented 
to the leading Jesuits of the Roman College. 

After exhibiting on several occasions in the 
garden of the Quirinal Palace, belonging to 
Cardinal Bandini, all his recent discoveries, or 
" celestial novelties " as they were called, a 
commission of four scientific members of the 
Roman College was appointed, at the request of 
Cardinal Bellarmine, to examine and report. As 
the result, the commissioners, Fathers Clavio, 
Griemberger, Maelcote, and Lembo, were con- 
strained to admit what they had long denied 
and ridiculed, being now convinced by ocular 
proofs of the truth of the facts announced by 
Galileo. By this opinion (given on 24th April) 
of the Papal experts, his discoveries received to 
a certain extent the sanction of the Church. 
Attentions of all sorts were now heaped upon 
him ; Pope Paul V. granted him a long audience, 
and assured him of his unalterable good-will, 
which, however, did not remain so, as the sequel 
will show. High dignitaries of the Church 
followed suit, and were lavish in their admiration ; 


and the Accademia dei Lincei (founded in 1603 
by Prince Cesi), the prototype of our Royal 
Society, elected him a member. So that when he 
took his departure, on the 4th of June, Galileo 
left behind in Rome many sincere friends and 
admirers, and some very envious foes. 

A letter of 3ist May, from Cardinal del Monte 
to Cosimo II., will best show how Galileo's friends 
regarded his visit. 

"Galileo has, during his stay in Rome, given 
great satisfaction, and I think he must have felt 
it no less himself, for he had the opportunity of 
showing his discoveries so well, that to all clever 
and learned men here they seemed no less true 
and well-founded than astonishing. Were we 
still living under the ancient republic of Rome I 
verily believe there would have been a column 
on the Capitol erected in his honour/' 

Immediately after the publication of the report 
of the Bellarmine Commission, Galileo announced 
a new discovery in the heavens, namely, dark 
spots on the body of the sun, which, towards the 
end of April 1611, he showed to several prelates 
and savants in Rome. 

Describing these phenomena at a later date 1 
Galileo states that at first he was undecided 
whether to explain the ever-changing nature, and 
position of the spots by supposing that the sun 
revolved on his own axis, or by imagining that 
other unknown stars, besides Mercury and Venus, 
revolved about the sun, which were visible only 
as spots, and invisible at other times on account 

1 " Discourse on Floating Bodies," Florence, 1612. 

i6i2] SUN-SPOTS 129 

of their small distance from him. But further 
observation led him to abandon the latter sup- 
position and to announce positively 1 that the 
spots were in actual contact with the body of 
the sun, where they were continually appearing 
and disappearing, much as clouds about our 
earth ; that their figures were very irregular, 
some being very dark and others less so ; that 
one would often divide into two or three, and at 
other times two or three would unite into one ; 
and that they all had a common and regular 
motion, being carried round with the sun, which 
turned on its axis in a little less than a lunar 
month, 2 and in the same direction as the planets. 

These observations were, in their consequences 
to Galileo, particularly unfortunate, as in the course 
of the controversy in which they entangled him, he 
first became personally embroiled with the powerful 
Jesuit party, whose influence was one of the chief 
causes of his subsequent misfortunes. 

A Jesuit father, Christopher Scheiner, Professor 
of Mathematics at Ingolstadt, claimed priority in 
the discovery of the Sun-spots, asserting that early 
in 1611 he first noticed them and showed 
them to his pupils. Scheiner stated his case in 
three letters over the signature Apelles latens 
post tabulam, and addressed to Mark Welser, 
Chief Magistrate of Augsburg. In the first 
letter dated i2th November 1611, he states 
that he made his first observations seven months 
previously ; but apparently he then attached no 

1 Letter to Prince Cesi, dated i2th May 1612. 

2 Modern observations make it vary from 25 to 27 J days. 



value to them, for, on resuming his work in the 
following October, he thought the appearances 
arose from some defect in his glasses an idea 
which was only dissipated by these further studies, 1 
Clearly then, it was only after resuming his observa- 
tions (October 1611) that he believed in the actual 
existence of the spots, which he then explained 
by supposing them to be caused by multitudes of 
little planets, revolving round the sun in an orbit 
inside Mercury, and producing the appearance of 
spots in crossing his disc. 

On the publication of Schemer's letters at 
Augsburg, Welser, on 6th January 1612, sent a 
copy to Galileo requesting to be favoured with his 
opinions of the phenomena therein described. 
Galileo replied in three letters 2 in which he easily 
combated Scheiner on the nature of the spots, 
and stated that his own observations dated back 
eighteen months. 8 

1 An amusing incident is related in connection with Schemer's 
observations, which shows how the authority of Aristotle held its 
ascendency over men's minds even when his dogmas were opposed 
to the testimony of the senses. On communicating his discovery to 
the Provincial of his Order, the latter replied : " I have read 
Aristotle's writings from end to end many times, and I can assure you 
I have nowhere found anything similar to what you describe. Go, my 
son, and tranquillise yourself ; be assured that what you take for spots 
on the sun are the faults of your glasses, or of your eyes." Scheiner 
was only permitted to publish his observations anonymously, as 
mentioned in the text. 

2 The first of which, dated 4th May 1612, is now in the British 
Museum in autograph ; the second is dated I4th August, and the 
third ist December. All three were published in 1613 under the 
title " Istoria e Dimostrazioni delle Macchie Solari." 

3 He says this at the beginning of the first letter, which is dated 
4th May 1612. This would fix the date at about beginning of 
November 1610 ; yet, from Fra Micanzio's letter to Galileo of 
27th September 1631, the first observations would appear to go back 


In these letters Galileo further stated that the 
spots often dispersed like vapours or clouds, which 
he supposed them to be ; that they sometimes lasted 
only one or two days, and at other times thirty or 
forty days ; that they contracted in breadth as 
they approached the sun's limb, without diminishing 
their length ; that they described circles parallel to 
each other; that the rotation of the sun again 
brought the same spots into view ; and that they 
were never seen to extend to a greater distance 
than 30 from the sun's equator. 1 

Besides the spots, Galileo's telescope disclosed 
other interesting appearances on the sun's disc. 
Some parts are perceived to be brighter than the 
rest of the surface, and hence are called faculae. 
These phenomena are described in the third letter 
to Welser, where with great acuteness he adduces 
them as a proof that the spots are attached to the 
surface of the sun, and are not little planets as 
Scheiner supposed ; for the telescope frequently 
showed spots and faculae travelling across the sun's 
disc together ; and, accepting Schemer's supposition 
with regard to the former, it would be probable 
that the latter also should sometimes appear as 
bright spots beyond the sun's limb a conclusion 
which was totally at variance with all his observa- 

These letters were written from the Villa delle 
Selve of his friend Filippo Salviati, near Signa 

to the time when Galileo was still at Padua, say to August But 
writing so long after the event, Micanzio may well be mistaken as to 
the date. 

1 Appended to the second letter are forty sketches of the spots as 
observed from day to day during June, July, and August 1612. 


(9 fniles from Florence), where Galileo spent much of 
his time at this period, and particularly during his 
frequent indispositions, as he considered that the 
air of the city was prejudicial to his complaints. 1 

The letters, with Schemer's appended, were 
printed at Rome in March 1613, and were dedicated 
to Salviati. They were published under the 
auspices of the Accademia dei Lincei, " In order," 
as the Academy report sets forth, "to mark its 
sense of the merit of the work and the claim of its 
author to be regarded as the first discoverer of 
Sun-spots/' 2 

In order to complete our history of the Sun- 
spots in so far as Galileo is concerned, we have 
left unnoticed other important matters on which 
he was at the same time engaged, and to these 
we must now return. Soon after his return to 
Florence in June 1611, he wrote a pamphlet in 
the usual form of a letter, dated ist September 
1611, and addressed to Father Griemberger, "on 

1 Salviati had ever been one of his wannest friends, and delighted 
in drawing round him all the great scientists of the time. He was a 
member of the Accademia dei Lincei, and although not an author of 
any great work, or of any important discovery, he has yet earned, by 
his liberality to science, and by his devotion to Galileo, an honoured 
name that will not die. He died 22nd March 1614, and in after years 
Galileo raised to his memory a monument more enduring than 
marble, by assigning to him the place of honour in the immortal 
Dialogues of 1632, where Salviati is the Copernican interlocutor, and 
represents, in fact, Galileo himself in the dialogue. 

2 The first discovery of Sun-spots has also been claimed for 
Thomas Hariot in England, for Simon Mayer in Germany, and for 
Johann Fabricius in Holland. The first two claims rest on very 
doubtful evidence ; the third is better founded. In fact, Fabricius 
was the first to publish the results of his observations in his " De 
Maculis in Sole Observatis" (Wittenberg, June 1611), and therefore, 
according to modem notions, he has the best claim to priority. For 
more, see Grant's " History of Physical Astronomy," pp. 213-15. 


the Inequalities of the Moon's surface," or lunar 
mountains. The moon was with him a stock 
subject for observation, the results of which he 
communicated from time to time in letters to 
(besides Griemberger) Welser, Brengger, Gallan- 
zoni, and others. Indeed, his last astronomical 
discovery, towards the close of life and just before 
he became blind, was connected with the moon. 

It had been asserted that, as the full moon 
always presented a well-defined outline, whether 
when viewed with the naked eye, or through a 
telescope, it was impossible that there could exist 
any equalities around her circumference. Galileo, 
however, maintained that the irradiation of the 
moon's light, by obliterating any asperities around 
her edge, might effectually conceal the real nature 
of that part of her surface. With respect to 
irradiation generally, he remarked that it increases 
with the brightness of the object. It is from this 
cause that the planets near the sun have a greater 
irradiation than those that are more remote. So 
intense is the irradiation of Mercury, that it is 
impossible, even with the most powerful telescope, 
to deprive him of his brilliant corona. The same 
is true, though in a less degree, with respect to 
Mars. On the other hand, Jupiter, and especially 
Saturn, being more feebly illuminated by the solar 
light, lose their irradiation in the telescope, and 
disclose their true figures. With respect to Venus, 
when she is near her inferior conjunction, she 
resembles the new moon ; but such is the intensity 
of her irradiation, that she appears to the naked 
eye like any other star. In this position, however, 


as the extent of the illuminated surface, is small, and 
the light is at the same time enfeebled by the 
obliquity of the surface, it is possible by means of 
a telescope to discern the real appearance of the 
planet. When, however, she is near her superior 
conjunction, she presents a complete hemisphere 
of vivid light towards the earth of such intensity 
that even the most perfect telescope does not 
suffice to destroy her irradiation and reveal to 
us her true figure. 

Galileo, therefore, contends that since the 
effect of irradiation is so great as to conceal from 
the unaided eye the immense cavity of Venus 
when she assumes the form of a crescent, it is 
much more probable that a telescope will fail to 
efface the irradiation of the moon enough to dis- 
close the small eminences and cavities which may 
be situated near the edge of her disc. 1 

Like all subsequent observers up to the close 
of the eighteenth century, Galileo is said to have 
believed in the existence of lunar seas and of a 
lunar atmosphere ; while on the question of the 
existence of lunar inhabitants he is supposed to 
have kept an open mind. 2 His belief in a lunar 
atmosphere may be conceded, but as regards the 

1 See p. 88 ante. Also Grant's " History of Physical Astronomy," 
PP- 347-52. In one of the frescoes in the Borghese chapel in S. Maria 
Maggiore, Rome (the Virgin with the moon under foot), by Cigoli, the 
friend and correspondent of Galileo, the hills and valleys of the moon 
are painted as the telescopes of the day (1612) revealed them. 

2 As regards the habitation of the planets, however, he was dis- 
creetly silent. In a letter to Prince Cesi, 25th January 1613, he says : 
" If the question be put to me I will answer neither yes nor no." He 
also refers to tr^e subject in the same indeterminate way in his letters 
on Sun-spots and in the Dialogues of 1632. 


other points the very reverse is the fact, as the 
following letter shows. Writing to Giacomo Muti 
from Rome, on 2 8th February 1616, Galileo 
says : 

"A few days ago, when paying my respects to 
the illustrious Cardinal Muti, a discussion arose on 
the inequalities of the moon's surface. Signor 
Alessandro Capoano, in order to disprove the 
fact, argued that if the lunar superfecies be unequal 
and mountainous, one may say as a consequence 
that, since Nature has made our earth mountainous 
for the benefit of plants and animals beneficial to 
man, so on the moon there must be other plants 
and other animals beneficial to other intellectual 
creatures. Such a consequence, he said, being 
most false, therefore the fact from which it is 
drawn must also be false, therefore lunar mountains 
do not exist ! l To this I replied : As to the in- 
equalities of the moon's surface we have only to 
look through a telescope to be convinced of their 
existence ; as to the consequences/ I said, they 
are not only not necessary, but absolutely false 
and impossible, for I was in a position to prove 
that neither men, nor animals, nor plants as on 
this earth, nor anything at all like them can exist 
on the moon. I said then, and I say now, that I 
do not believe that the body of the moon is 
composed of earth and water, and wanting these 
two elements we must necessarily conclude that it 
wants all the other things which without these 
elements cannot exist or subsist I added further : 
even allowing that the matter of the moon may be 
like that of the easfh (a most improbable 
supposition), still not one of those things which 

1 The work of the peripatetic philosopher Lagalla ("De Phoeno* 
menis in Orbe Lunae," Bologna, 1612), enforcing the same arguments, 
is reprinted in the later editions of Galileo's works, with his marginal 


the earth produces can exist on the moon, since 
to their production other things besides earth 
and water are necessary namely, the sun the 
greatest agent in Nature and the resulting 
vicissitudes of heat and cold, and of day and night. 
Now, such vicissitudes are on the moon very 
different from those on the earth. In the latter 
case, to produce a diversity of seasons, the sun 
rises and falls more than 47 (in passing from 
one tropic to the other); in the former case the 
variation is only 5 on each side of the ecliptic. 
While, therefore, on the earth the sun in every 
24 hours illuminates all parts of its surface, each 
half of the moon is alternately in sunshine and 
darkness for 15 continuous days of 24 hours. 
Now, if our plants and animals were exposed to 
ardent sunshine every month for 360 consecutive 
hours, and then for a similar time were plunged 
in cold and darkness, they could not possibly 
preserve themselves, much less produce and 
multiply. We must, therefore, conclude that what 
would be impossible on our earth under the circum- 
stances we have supposed to exist, must be impossible 
on the moon where those conditions do exist." 

No sooner were these questions of sun-spots 
and lunar mountains out of hand than Galileo 
became engaged in another protracted discussion, 
which resulted in another famous treatise, pub- 
lished in Florence in 1612. This is his " Discourse 
on Floating Bodies," in which he uses the principle 
of virtual velocities from which modern geometers, 
and especially Lagrange, have drawn largely, and 
by the aid of which he demonstrates the more 
important theorems of hydrostatics. 1 

1 This important principle was first announced in his treatise on 
Mechanics, written in 1594. See p. 37 ante. 


The question of floating bodies had been dis- 
cussed at one of the scientific parties which the 
Grand Duke liked to assemble round him, and the 
general opinion appearing to be that of Aristotle, 
that the floating or sinking of a body depended 
principally upon its shape, Galileo undertook to 
show its untenableness. Some one in the company 
asserted that condensation is the effect of* cold, and 
ice was mentioned as an instance. Galileo retorted 
that ice is rather water rarefied than water con- 
densed, the proof of which is that it always floats 
upon water. His opponents rejoined that this 
phenomenon was due, not to the lightness of the 
ice, but to its incapacity, owing to its flat shape, 
to overcome the resistance which the water opposed 
to its sinking. Galileo denied this, and asserted 
that ice of any shape would float upon water, and 
that if a flat piece of ice were forced to the bottom 
it would, when left to itself, rise again to the 
surface. 1 

The general character of this remarkable Dis- 
course will be understood from the following 
passages : 

"The diversity of figure given to any solid 
cannot be the cause of its floating or sinking in 
water ; so that if a solid made, for instance, into 
a sphere sinks or floats, it will likewise sink or 
float when made into any other form. The breadth 
of the figure may indeed retard its velocity as well 
of ascent as of descent, and more and more in 
proportion to the breadth and thinness of the said 

1 Cardinals Gonzaga and Maffeo Barberini (afterwards Pope 
Urban VIII.) were among the guests, and the latter took Galileo's 
side in the discussion against the peripatetics led by Gonzaga. 


figure ; but that it can be reduced to such a form 
as to put an end to its motion I hold to be im- 
possible. In this I have met with opponents who, 
pointing to some experiments, and, in particular, 
taking a thin board of ebony and a ball of the 
same wood, and showing that the latter sinks, while 
the former, if placed lightly on the surface, floats, 
hold by the opinion of Aristotle that the cause 
of flotation is the breadth of the figure, which 
renders it unable to overcome the resistance of 
the water to penetration ; whereas in the case of 
the ball its form enables it to overcome this re- 
sistance, and it readily sinks. I assert, on the 
contrary, that there is not any solid of such light- 
ness or of such a figure that, being placed on the 
water, will not divide and penetrate it ; and if 
you examine carefully your thin boards of wood 
you will see that they have part of their thickness 
under water ; and, moreover, you will see that 
shavings of ebony, stone, and metal, when they 
float, have not only broken the continuity of the 
water, but are with all their thickness under the 
surface, and this more and more according to their 
specific gravity; so that a thin plate of lead will 
be lower than the surface of the surrounding water 
by at least twelve times the thickness of the plate, 
and a gold plate will dive below the level almost 
twenty times its thickness/' 

In order to show more clearly the non-resistance 
of water to penetration, Galileo then directs a cone 
to be made of wood or wax, and asserts that when 
it floats, either with its base or its apex in the 
water, the solid content of the part immersed will 
be the same, although the apex is (by reason of 
its shape) better adapted to overcome the resist- 
ance of the water to division. The shape, then, 


cannot be the cause of the buoyancy. Or the 
experiment may be varied by mixing the wax with 
lead filings till the compound sinks in water, when 
it will be found that in any shape the same weight 
of cork must be added before it will rise to the 
surface. He goes on : 

" This silences not my antagonists, who say that 
my experiments import little to them, and that it 
is enough for them to have demonstrated in one 
instance, and in such manner as pleases them best, 
that an ebony ball when put into water sinks to 
the bottom, while an ebony board stays to swim 
at the top, and the matter being the same, and 
the two bodies differing in nothing but in figure, 
they affirm that with all perspicuity they have 
demonstrated and sensibly manifested what they 
undertook. Nevertheless, I believe and think I 
can prove that this very experiment proves nothing 
against my theory. And first, it is false that the ball 
sinks and that the board does not; for the board 
will sink too, if you do to both as the words of 
our question require ; that is, if you put them both 
in the water ; for to be in the water implies to be 
placed in the water; and, by Aristotle's own 
definition of place, to be placed imports to be 
environed by the surface of the ambient body. 
But when my antagonists show the floating board 
of ebony they put it not into the water, but upon 
the water, where, being detained by a certain 
impediment (of which more anon), it is surrounded 
partly by water, partly by air, which is contrary 
to our agreement, for that was that the bodies 
should be in the water, and not part in the water, 
part in the air. I will not omit another reason, 
founded upon experience, and, if I deceive not 
myself, conclusive against the notion that figure 
and the resistance of the water to penetration have 


anything to do with the buoyancy of bodies. 
Choose a piece of wood or other matter, as for 
instance walnut-wood, a ball of which rises from 
the bottom of the water to the surface more slowly 
than a ball of ebony of the same size sinks, so 
that clearly the ball of ebony divides the water 
more readily in sinking than does the walnut in 
rising. Then, take a board of walnut-wood equal 
to and like the floating ebony of one of my anta- 
gonists, and if it be true that this latter floats by 
reason of the figure being unable to penetrate the 
water, the other of walnut- wood, without all question, 
if thrust to the bottom ought to stay there, as 
having the same impeding figure, and in conse- 
quence unable to overcome the said resistance of 
the water. But if we find by experience that not 
only the thin board, but every other figure of the 
same walnut-wood, will return to float, as un- 
questionably we shall, then I must desire my 
opponents to forbear to attribute the floating of 
the ebony to the figure of the board, since the 
resistance of the water is the same in rising as in 
sinking, and the force of ascension of the walnut- 
wood is less than the ebony's force for going to 
the bottom. 

c< Now, let us return to the thin plate of gold or 
silver, or the thin board of ebony, and let us lay it 
lightly upon the water, so that it may stay there 
without sinking, and carefully observe the effect. 
It will appear clearly that the board or plate is 
lower than the surface of the water, which rises up 
and makes a kind of rampart round it on every side. 
But if it have already penetrated and overcome the 
continuity of the water, and is of its own nature 
heavier than the water, why does it not continue 
to sink, but stop and suspend itself in that little 
dimple that its weight has made in the water ? My 
answer is, because in sinking till its surface is below 


the water, which rises up in a bank round it, it draws 
after and carries along with it the air above it, so 
that that which descends is not only the board of 
ebony (or metal plate), but a compound of ebony 
and air, from which composition results a body no 
longer specifically heavier than the water, as was 
the ebony or metal alone. But, gentlemen, we 
want the same matter; you are to alter nothing 
but the shape, and therefore have the goodness to 
remove this air. This may be done simply by 
washing the upper surface of the board, for the 
water having once got between the board and the 
air will run together, and the ebony will sink to 
the bottom ; and if it does not, you have won the 
day. But methinks I hear some of my antagonists 
cunningly opposing this, and telling me that they 
will not on any account allow their board to be 
wetted, because the weight of the water so added, 
by making it heavier than it was before, forces it 
to the bottom, and that the addition of new weight 
is contrary to our agreement. 

"To this I answer first, that nobody can 
suppose bodies to be put into water without wetting 
them, nor do I wish to do more to the board 
than you do to the ball. Moreover, it is not true 
that the board sinks on account of the weight of 
the water added in the washing ; for I will put ten 
or twenty drops on the floating board, and so long 
as they stand separate it shall not sink ; but if the 
board be taken out, and all that water wiped off, 
and the whole surface be bathed with a single drop, 
and be again put upon the water, there is no 
question but it will sink, water running to cover it, 
being no longer hindered by the air. In the next 
place, it is altogether false that water can in any way 
increase the weight of bodies immersed in it, for 
water has no weight in water, since it does not sink. 
Now, just as he who should say that brass by its 


own nature sinks, but that when formed into a 
kettle it acquires from that figure a virtue of lying 
in the water without sinking, would say what is 
false, because that is not purely brass which then is 
put into the water, but a compound of brass and 
air ; so is it neither more nor less false that a thin 
plate of brass or ebony swims by virtue of its dilated 
and broad figure. 

" Some may wonder that I affirm this power to 
be in the air of keeping a board or metal plate from 
sinking, as if in a certain sense I would attribute 
to the air a kind of magnetic virtue for sustaining 
heavy bodies with which it is in contact. To satisfy 
all these doubts, I have contrived the following 
experiment to demonstrate how truly the air does 
support these solids ; for I have found, when one of 
these bodies (which floats when placed lightly on 
the water) is thoroughly bathed and sunk to the 
bottom, that, by carrying down to it a little air, 
without otherwise touching it in the least, I am able 
to raise and carry it back to the top, where it floats 
as before. To this effect I take a ball of wax, and 
with a little lead make it just heavy enough to sink 
very slowly to the bottom, taking care that its 
surface be quite smooth and even. This, if put 
gently into the water, submerges almost entirely, there 
remaining outside only a very little of the top, and, 
so long as it is thus joined to the air, the ball floats ; 
but if we take away the air, by wetting this top, the 
ball sinks to the bottom, and remains there. Now 
to make it return to the surface by virtue of the air 
which before sustained it, thrust into the water 
a glass, with the mouth downwards, which will 
carry with it the air it contains ; move this down- 
wards towards the ball, until you see that the air 
has reached the top of it ; then gently draw the 
glass upwards and you will see the ball rise, and 
afterwards stay on the top of the water, if you 


carefully withdraw the glass without too much 
disturbing the water. There is therefore a certain 
affinity between the air and other bodies, which 
holds them united, so that they separate not without 
a kind of violence, just as between water and other 
bodies ; for in drawing such bodies wholly out of 
the water, we see it follow them, and rise sen- 
sibly above the level before it quits them/' 

His opponents were in hopeless confusion 
between the phenomena of hydrostatic pressure, 
which they professed to be discussing, and those of 
capillary action which they quoted against Galileo. 
With his careful observations to support him, 
Galileo would have carried conviction more readily 
had he emphasised the distinction between the two 
questions, and realised himself that the floating 
plate of metal indicated a natural property of 
liquids which deserved special investigation. 

Having established his theory of buoyancy by 
these ingenious experiments, Galileo proceeds to 
show what must be the dimensions of a plate of 
any substance which will float as the wax does, 
assuming in each case that we know the greatest 
height at which the rampart of water will stand 
round it In like manner he shows that a 
pyramidal or conical figure may be made of any 
substance in such a way that, by the help of the 
air, it shall rest upon the water without wetting 
more than its base ; and, furthermore, that we 
may form a cone of any substance so that it shall 
float (partially submerged) if placed gently on the 
surface with its point downwards, whereas no care or 
pains will enable it to do so with its base down- 


wards, owing to the different proportions of air which 
in the two positions are in contact with the water. 1 

As may be gathered from the foregoing ex- 
cerpts, the book contains many ingenious experi- 
ments and much acute reasoning in support of 
the true principles of hydrostatics. Like all his 
other works it encountered violent opposition, and 
Galileo had, more than once, to enter the field to 
repel the counter " arguments " of his opponents. 
The first published attack was by Giorgio Coresio, 
a professor in Pisa, under the form of a letter to 
the Archbishop of Florence. The reply to this was 
entrusted to Galileo's valiant disciple and champion, 
Benedetto Castelli. The manuscript was submitted 
to the Master and revised by him, and was about to 
be published when Coresio was dismissed (on its 
leaking out that though professedly a Catholic he 
really belonged to the Greek Church), and died soon 
after. Thereupon, the work was laid aside, on the 
principle de mortuis nil nisi bonum. A second attack 
was published anonymously, but was well known to 
be the work of Arturo d'Elci, head of the University 
of Pisa, the same who, as we shall presently see, 
forbade any allusions in lectures to the astronomical 
discoveries of Galileo. To this Galileo replied in a 
long letter, dated 4th January 1613, and addressed 
to Tolomeo Nozzolini. 2 More elaborate attacks 
were next published by Lodovico delle Colombe 

1 Galileo took advantage of a second edition of this publication to 
record briefly his latest observations on Venus, on Jupiter's moons, and 
on the Sun-spots, all of which were, until then, only known to his friends 
and correspondents. This edition appeared in August, two months 
after the first. 

2 Nozzolini had previously defended Galileo's views against the 
attacks of d'Elci and Coresio in a letter (22nd September) to Mgr, 
Marzimedici. Archbishop of Florence. 

x6ia] CONTROVERSY 145 

and Vincenzio di Grazia. To these a detailed 
and overwhelming answer was printed in the name 
of Benedetto Castelli. After pulverising all the 
" arguments J> of his opponents, the writer taunt- 
ingly bids them remember that he was merely 
Galileo's pupil, and thence to conclude how much 
more effectually Galileo himself would have con- 
futed them had he thought it worth his while. 1 

It was in reference to this controversy that 
Galileo declared that ignorance had been the best 
master he ever had, since, in order to be able to 
demonstrate to his adversaries the truth of his 
conclusions, he had been forced to prove them 
by such a variety of experiments as made him- 
self doubly confident ; though to satisfy his own 
mind alone he had never felt it necessary to 
make many. 

1 It was not generally known till several years after Galileo's death, 
that Castelli's essay was in fact written by the Master himself. It 
is entitled "Risposta alle Opposizioni del Colombe e del Grazia," 
Florence, 1615. 






THE uncompromising boldness with which Galileo 
published and supported his opinions had, as we 
have seen so often, raised against him a host of 
enemies, who each had objections peculiar to him- 
self, but who now began to perceive the policy of 
uniting their strength in the common cause to 
crush, if possible, so strange an innovator. The 
Aristotelian professors, the Jesuits, the political 
churchmen, and those timid but respectable persons 
who at all times dread innovation, whether it be 
in religion or in science, all were drawn together 
against the philosophical tyrant who threatened 
them with the penalties of too much knowledge. 

The party of Galileo though weak in numbers 
was not without power and influence. He had 
trained around him a devoted band who idolised 
his genius, and disseminated his views, for many 
of his favourite pupils were now professors in the 
leading schools of Italy. 

No longer able to combat Galileo's hard facts 
and powerful arguments by asserting that the 
facts were faults in his glasses and instruments 


devilishly designed, and that his arguments were 
vain-glorious and "scientifically" absurd, his op- 
ponents now took their stand on theology, and 
raised the cry of the Church in danger. On the 
simple ground that his astronomical doctrines were 
incompatible with Scripture, a great din was raised 
and began to make itself heard, especially in 
Florence, early in the year 1612. 

With the first mutterings of the storm in his 
ears, Galileo wrote thus to Prince Cesi on I2th 
May in that year: 

" I suspect that this new discovery [the Sun- 
Spots] will be the signal for the funeral, or rather 
for the last judgment of the pseudo-philosophy 
the funereal signals having already been shown 
in the moon, the Medicean stars, Saturn, and 
Venus. And I expect now to see the peripatetics 
put forth some grand effort to maintain the im- 
mutability of the heavens!" 

True to her original attitude of hostility, 
Galileo's Alma Mater, Pisa, was consistent and 
persistent in her opposition to his teachings. 
Thus, Father Castelli, who in October 1613, was 
called to the Mathematical Chair in that Uni- 
versity, told Galileo (6th November 1613) that 
he was forbidden to treat in his lectures of the 
double motion of the earth, or even to hint at its 
probability ! " Of our controversies," he goes on 
to say, "not a word whatever, a thing which 
astonishes me. Your marvellous discoveries are 
scarcely known here even by name!" 

Notwithstanding all this commotion in the 
schools and amongst the minor churchmen, the 


authorities at Rome had not yet taken the alarm. 
On the contrary, we find the Cardinals Maffeo 
Barberini (afterwards Pope Urban VIII.) and 
Federigo Borromeo thanking Galileo for sending 
them his book on the Sun-Spots, and express- 
ing their admiration for his researches as described 
therein. Similarly, Battista Agucchia, one of the 
principal officials of the Papal Court, writing 8th 
June 1613, expressed his belief that Galileo's teach- 
ings would in time be universally acknowledged. 

" Although now they had many opponents, 
partly from their novelty and extraordinary char- 
acter, and partly from the envy and obstinacy of 
those who had from the first maintained the con- 
trary opinion." 

But amongst his other friends (not in Rome) 
there was at least one more discriminating, one 
who knew better the men and their spirit Fra 
Paolo Sarpi of Venice. This old and faithful 
friend did not share this confidence in the triumph 
of truth " I foresee," said he, " that the ecclesiastical 
authorities will change a question of physics and 
astronomy into one of theology, and that to my 
great grief Galileo, if he wants to live in peace and 
escape the charge of heresy, will have to recant." 
" The day will come," he continues, "when men of 
science will have to deplore the disgrace of Galileo." 
Prophetic words, as the sequel will show. 1 

An accidental circumstance was the spark which 
fired the train. One day in December 1613, 

1 Griselini, " Del Genio di Paolo Sarpi," Venice, 1785, vol. ii. p. 70. 
Professor Favaro, however, doubts their authenticity, and questions 
Griselini's authority. 


Castelli and other learned men were guests at 
the Grand Duke's table at Pisa, where, as usual, 
the Tuscan Court was wintering. The conversa- 
tion turning on the " satellites of Jupiter,' 1 Castelli 
took the opportunity of extolling and expatiating 
on his master's discoveries, One of the guests, 
Boscaglia, Professor of Physics at the University, 
and a peripatetic of the purest water, managed to 
excite the religious scruples of Cristina, Dowager 
Grand Duchess, by telling her that all Galileo's 
telescopic discoveries were true, only the deduction 
from them of the double motion of the earth must 
be wrong, as the Holy Scriptures were clearly 
opposed to such a doctrine. Castelli, who had 
left the apartment, was recalled to answer this 
objection. At first he deprecated bringing the 
Bible into the controversy, but as this was un* 
availing, he resolutely took the theological stand- 
point, and defended the new views of the universe 
so well, that many of those present took his side 
the Dowager Duchess standing alone, and Boscaglia 
taking no part. Castelli hastened to apprise 
Galileo of this incident, and added that it appeared 
to him that the Grand Duchess had merely per- 
sisted in opposition, in order to draw him out. 
(Letter of i4th December 1613.) 

This, then, was the provocation to Galileo's 
famous letter of 2ist December 1613 to Castelli, 
in which for the first time he engages in theological 
discussions, and which, although not intended for 
publication, was to be turned to account by his 
enemies, and to form the groundwork of his 
subsequent trial. The letter is too long to quote 


in full, but the following passages will show the 
line of argument pursued. 1 He begins by showing 
that there is as much difficulty in reconciling the 
Ptolemaic as the Copernican system of the world 
with the astronomical expressions contained in the 
Scriptures, and asserts that (the object of Scripture 
not being to teach astronomy) such expressions 
are there used as would be intelligible to the vulgar, 
and without regard to the true structure of the 
universe. 2 He then goes on: 

"As the Bible, although dictated by the Holy 
Spirit, admits (for the reasons given above) in 
many passages of an interpretation other than 
the literal one, and as, moreover, we cannot maintain 
with certainty that all interpreters are inspired by 
God, I think it would be the part of wisdom not to 
allow any one to apply passages of Scripture in such 
a way as to force them to support as true any 
conclusions concerning nature, the contrary of 
which may afterwards be revealed by the evidence 
of our senses, or by actual demonstration. Who 
will set bounds to man's understanding ? Who can 
assure us that every thing that can be known in the 
world is known already? ... I am inclined to 
think that Holy Scripture is intended to convince 

1 This letter, with the one from Castelli which called it forth, is 
given in full in "Private Life of Galileo," London, 1870, pp. 73-7. 

2 When the intrigues against Galileo began in, Florence 1611-12, 
he consulted Cardinal Conti as to how far the Scriptures were 
favourable to the Aristotelian constitution of the world. Conti 
replied, 7th July 1612, that the Scriptures were rather contrary than 
favourable to the peripatetic doctrine of the incorruptibility of the 
heavens ; but he was not so sure on the question of the motion of the 
earth. He thought that this opinion could not be reconciled with 
passages in Scripture which attributed motion to the sun and stars 
only, except on the assumption that the Scriptures employed a popular 
form of expression a form understandable by the vulgar, but which 
was not necessarily and rigorously true to the facts. 


men of those truths which are necessary for their 
salvation, and which being far above man's under- 
standing cannot be made credible by any learning, 
or by any other means than revelation. But that 
the same God who has endowed us with senses, 
reason, and understanding, does not permit us to 
use them, and desires to acquaint us in another way 
with such knowledge as we are in a position to 
acquire for ourselves by means of those faculties 
that, it seems to me I am not bound to believe, 
especially concerning those sciences about which 
the Holy Scriptures contain only small fragments 
and varying explanations ; and this is precisely 
the case with astronomy, of which there is so little 
that the planets are not all enumerated, only the 
sun and moon, and once or twice Venus under 
the name of Lucifer. This, therefore, being 
granted, I think that in discussing natural 
phenomena we ought not to begin with texts 
from Scripture, but with experiment and de- 
monstration, for from the Divine Word Scripture 
and Nature do alike proceed. And I can see that 
that which experience sets before our eyes con- 
cerning natural effects, or which demonstration 
proves unto us, ought not upon any account to 
be called in question, much less condemned, upon 
the testimony of Scriptural texts, which may 
(under their mere words) have meanings of a 
contrary nature. ..." 

The letter concludes with a long discussion of 
Joshua's miracle, ending in a reductio ad absurdum. 

Castelli, seeing nothing objectionable in this 
letter, gave it a wide circulation in written copies. 
But not so the enemies of Galileo, who eagerly 
seized it as a weapon to be used against him. 
They turned his emphatic opinion that the Scrip- 


tures had no business in scientific controversy 
into the reproach that he assailed the universal 
authority of the Bible, and, referring to his 
explanation of Joshua's miracle, they loudly 
demanded that the Scriptures must be protected 
from the arbitrary interpretations of profane lay- 

After some months of underhand agitation, 
Father Caccini of the Dominican convent of San 
Marco was the first to declare war openly, in a 
sermon from the pulpit of Santa Maria Novella 
in Florence. Preaching on the fourth Sunday 
in Advent (December) 1614, an< i selecting as his 
texts chap. x. vers. 12, 13, of Joshua, and chap. i. 
ver. n, of Acts, he began with the words: 
11 Ye men of Galilee ! why stand ye gazing 
up into heaven ?" He asserted that Galileo's 
doctrine of the earth's revolution round the 
sun was irreconcilable with the holy Catholic 
faith, since it contradicted several passages in 
Scripture. He reminded his hearers that no one 
was permitted to interpret the Bible in any other 
sense than that adopted by the Fathers; he as 
good as denounced Galileo's teachings as heretical ; 
and wound up with a coarse attack on mathe- 
maticians in general, whose science he called 
an invention of the devil, and who should be 
banished from all Christian states, since all 
heresies proceeded from them. A preacher at the 
Puomo (cathedral), a Jesuit strange to say, replied, 
and undertook to show that Copernicus was right ; 
that Galileo and his followers were good Catholics ; 
and that Caccini and the Dominicans generally were 


ignorant fools! As may be imagined, this line 
of argument added fuel to the fire, and the result was 
a great commotion in Florence. This fierce attack 
made Galileo lose patience ; he wished to publicly 
resent the insults, but on the advice of friends 
he kept quiet, and the storm subsided for a while. 
The man who first brought Galileo's affairs 
before the Inquisition (or the Holy Office) was 
one Father Lorini, a friend of Caccini and a 
member of the same convent This man was 
Professor of Ecclesiastical History in Florence, 
and was from the beginning of 1612 a ringleader 
of all the local intrigues against Galileo. A copy 
of the letter to Castelli had come into his 
hands, and this, after Caccini's fierce sermon, he 
sent to the Holy Office in Rome with an un- 
signed denunciation, dated 5th February 1615, 
and addressed to Cardinal Mellini, President of 
the Congregation of the Index. This document 
was most artfully drawn up ; too cowardly to 
mention Galileo by name, as he knew him to 
have friends at the Vatican, he denounces the 
Galileists in general, "who maintain agreeably to 
the doctrine of this man Ipernic, or whatever 
they call him, that the earth moves and the 
heavens stand still." "All the fathers," he goes 
on, "of this devout convent of San Marco find 
many passages in this letter which are suspicious 
and presumptuous, as when it says (i) that many 
expressions of Holy Scripture are indefinite; 

(2) that in discussions about natural phenomena 
the lowest place must be assigned to them ; 

(3) that the commentators have often been mis- 


taken in their interpretations ; (4) that the 
Scriptures should not be mixed with anything 
but matters of religion ; (5) that in nature philo- 
sophical and astronomical evidence is of more 
value than Holy writ ; arid finally (6) that when 
Joshua commanded the sun to stand still we 
must only understand that the command was 
addressed to the primum mobile, and not to the 
sun " ; and so on, and so on. 

In consequence of this denunciation the Holy 
Office instituted a secret enquiry. As Lorini had 
only sent a copy of the letter to Castelli, the 
Inquisition took steps to gain possession of the 
original, written and signed by Galileo, and wrote 
(26th February 1615) to the Archbishop of Pisa 
to procure the document "in a skilful manner." 
But in this they were foiled ; Castelli no longer 
possessed the letter, having returned it to Galileo, 
and the latter, on being asked for it again, 
supplied only a copy, unsigned and undated, and 
which, moreover, he strictly enjoined Castelli not 
to let out of his hands. Castelli accordingly read 
the letter to Archbishop Bonciani (in presence of 
several canons of his cathedral), who concealed 
as well as he could his annoyance at the failure 
of his scheme. So, Cardinal Mellini had to be 
content with Lorini's copy of the incriminated 
letter, which was submitted to the Councillor of 
the Holy Office for his opinion. His report was 
a colourless one : some passages were objectionable, 
but, although at first sight they looked ill, they 
were capable of being taken in a good sense, 
and on the whole the document was not of that 


nature that it could be said to deviate from 
Catholic doctrine. 

Meanwhile, Caccini, who had been transferred to 
Rome, was summoned as one specially well-informed 
about Galileo's teachings! His evidence was a 
repetition of his sermon, mixed up with all the 
tittle-tattle of Florence. After denouncing Galileo 
and his works as Godless, he concluded, "at any 
rate he is suspicious in religious matters, because 
he belongs to a certain Accademia dei Lincei, 
and corresponds with the Godless Fra Paolo 
Sarpi at Venice, and with many Germans." 

Galileo appears to have known nothing ac- 
curately of these proceedings. He could only 
learn that some Dominican monks were making 
use of his letter to Castelli in order to effect 
the condemnation of the Copernican doctrines. 
Fearing that the copy on which they relied at 
Rome might have been tampered with, he sent a 
correct copy, on i6th February 1615, to his friend 
and old pupil, Mgr. Piero Dini, with a request that 
he would forward it to Father Griemberger, and 
perhaps also to Cardinal Bellarmine. He added 
that he had written to Castelli currente calamo^ 
and that he had since made many researches 
into the matters therein discussed, which he was 
embodying in a larger treatise a copy of which 
when finished he would send. 1 Mgr. Dini in 
reply, and apparently as the result of a con- 
ference with Cardinals del Monte and Bellarmine, 
urged Galileo to hurry on his writing, but at the 

1 This was his celebrated letter or Apology addressed to the 
Grand Duchess Cristina. 


same time advised caution, to avoid theology, 
and to confine himself to mathematics and physics. 
" Write freely," he said, "but be careful to keep 
outside the sacristy." Mgr, Ciampoli, another 
(Florentine) disciple then residing in Rome, writ- 
ing 28th February, conveyed the assurance of 
Cardinal Maffeo Barberini that he had Galileo's 
interests at heart, and that it would be more 
prudent not to go beyond his role of Professor 
of Mathematics, as the theologians claimed to 
have the sole right of explaining the Scriptures. 
Prince Cesi gave him much the same advice, 
and added his belief that any deliberate formu- 
lation of the, Copernican doctrine would only end 
in its prohibition, and the suppression of his book. 
This excellent advice unfortunately came too late, 
for, as we see, the Inquisition was already moving ; 
and even if Galileo had never written his letter 
to the Grand Duchess, or had written it in the 
way suggested, his enemies already had grounds 
enough to go upon. 

Although down to the end of June 1615, 
Galileo received reassuring letters from Rome, 
that there was nothing in progress at which he 
need be at all disconcerted, yet, so well did the 
Inquisition keep its secret, it was all the time 
laying its plans to entrap him. 1 

Meanwhile, about the middle of 1615, Galileo 

1 From 2oth June 1615, to Galileo's visit to Rome in the 
following December, but two letters from his Roman friends are 
extant, which, considering the anxious period covered, is remarkable. 
Von Gebler thinks it probable that Galileo destroyed the corre- 
spondence out of regard for his friends. " Galileo and the Roman 
Curia," London, 1879, P 64. 


completed his great apologetic treatise in the form 
of a letter to the Dowager Grand Duchess Cristina, 
in which he defines at great length his position as 
a natural philosopher, and as a sincere member of 
the Church of Rome. It is, naturally, an amplifica- 
tion of his letter to Castelli already quoted, and 
need not, therefore, be more fully noticed. 1 The 
pith of it is contained in the saying of Cardinal 
Baronius, which the author quotes : 

"The Holy Spirit intended to teach us in the 
Bible how to go to heaven, not how the heavens 

The concluding passages may be quoted as 
follows : 

" Again, to command professors of astronomy 
that they must themselves see to confuting their 
own observations and demonstrations is to ask 
the impossible, for it is not only to command 
them not to see what they do see, and not to 
understand what they do understand, but to seek 
for and to find the contrary. I would entreat 
these wise and prudent Fathers to consider 
diligently the difference between opinionative 
and demonstrative doctrines, to the end that 
they may assure themselves that it is not in the 
power of professors of demonstrative sciences to 
change their opinions at pleasure, and adopt first 
one side and then the other ; that there is a great 
difference between ordering a mathematician, or a 
philosopher, as to what opinion to hold, and doing 
the same with a merchant, or a lawyer, since 

1 Von Gebler gives an excellent rlsunU^ at pp. 64-70 of " Galileo 
and the Roman Curia." The Apology and the letter to Castelli were 
not published until after the trial of 1633, and then apparently with the 
object of showing the learned world how unjust his condemnation was. 


demonstrated conclusions touching things of nature 
and of the heavens cannot be changed with the 
same facility as opinions touching what is lawful, 
or not, in a contract, bargain, or bill of ex- 

" Therefore, let such people apply themselves 
to the study of the arguments of Copernicus and 
others, and leave the condemning of them as 
erroneous and heretical to whom it belongeth. 
Yet, as to this latter, they must not hope to find 
such rash and precipitate determinations in the 
wary Holy Fathers, or in the absolute wisdom of 
him who cannot err (the Pope), as those into 
which they suffer themselves to be hurried by 
some particular affection or interest of their own. 
In these, and such like opinions which are not 
directly articles of faith, certainly no man doubts 
that his Holiness hath always an absolute power 
of admitting or condemning them ; but it is not 
in the power of any creature to make them to be 
true or false, otherwise than as, in fact, they are." 

This letter, notwithstanding its moderate and 
even deprecating tone, was, of course, a fresh 
weapon against him, and his enemies denounced 
him more noisily than ever. Ominous reports 
began to circulate, but still Galileo could not learn 
any thing more definite than that something was 
brewing against him, and that the Copernican 
theory would probably be interdicted. Thinking 
that he could best combat these intrigues by 
going to Rome, he set out early in December 
1615, provided with cofdial letters from the Grand 
Duke to his Ambassador Guicciardini, to Cardinals 
del Monte and Orsini, and others. His enemies 
spread about that this step did not originate with 


himself, but was the result of a direct citation. 
This, however, is abundantly disproved by the 
Grand Dukes letters in which he distinctly says 
that Galileo goes to Rome of his own accord 

His reception by the authorities seemed to be 
cordial, but he quickly discovered that a zealous 
agitation was going on, not only against his teach- 
ings but against himself. However, he was con- 
fident that he should very soon destroy the traps 
of his enemies, and justify himself in a way that 
would bring discredit upon themselves. Judging 
from a letter of some days later, 23rd January 1616, 
to Secretary Picchena, he had not found his defence 
so easy as he anticipated. He says : 

"My business is far more difficult and takes 
much longer, owing to untoward circumstances, 
than the nature of it would require. I cannot 
communicate directly with those persons with whom 
I have to negotiate partly to avoid doing injury 
to any of my friends, and partly because they can- 
not communicate anything to me without running 
the risk of grave censure. So I am compelled 
with much pains and caution to seek out third 
persons who, without even knowing my object, 
may serve as mediators with the principals. . . . 
I have also to set down some points in writing, 
and to cause that they shall come privately into 
the hands of those whom I wish to see them." 

At length Galileo succeeded, as he thought, 
in freeing himself personally from all accusations 
and in refuting the slanders of Caccini and his 
confederates. The monk paid him a long visit, 
humbly begged pardon for his previous conduct, 


and offered any satisfaction in his power. But 
Galileo rightly gauged his sincerity, in a letter to 
Picchena of aoth February, in which he says : 

" I perceived not only his great ignorance, but 
that he has a mind void of charity and full of 

Lorini excused himself in a still more contemptible 
manner. He coolly admitted that he knew nothing 
and wanted to know nothing of the merits of the 
controversy. He only acted "for the sake of 
saying something, lest men should think that the 
Dominican Fathers were asleep or dead." 

But by adjusting his own difficulties Galileo 
had performed only half the task he set himself. 
The grander part of it, viz. the preservation of the 
Copernican doctrines from the interdict of the 
Church, had yet to be accomplished. 

" My business, so far as it concerns myself, is 
completed. All the exalted personages who have 
been conducting it have told me so plainly and 
in a most obliging manner, and have assured me 
that people are fully convinced of my uprightness 
and honour, and of the devilish malice and injustice 
of my persecutors. As far, therefore, as this matter 
is concerned I might return home without delay ; 
but there is a question connected with my case, 
which does not concern myself alone, but all those 
who during the last eighty years have advocated, 
in printed works and private letters, in public 
lectures and private conversations, a certain theory 
not unknown to your Excellency, on which they 
are now proposing to pronounce judgment. In 
the hope that my assistance may be of use in this 
matter, so far as a knowledge of those truths is 


concerned which are proved by the science to 
which I have devoted myself, I as a zealous and 
Catholic Christian neither can nor ought to with- 
hold that assistance which my knowledge affords ; 
and this part of the business keeps me fully em- 
ployed." (Letter to Picchena, 6th February 1616). 

As illustrating his manner of assisting the 
Copernican cause, the following letter from Antonio 
Querengo to Cardinal d'Este, 2oth January 1616, is 

"Your Reverence 1 would be delighted with 
Galileo if you heard him holding forth, as he often 
does, in the midst of fifteen or twenty, all violently 
attacking him, sometimes in one house, sometimes 
in another. But he is armed after such fashion 
that he laughs all of them to scorn ; and even if 
the novelty of his opinions prevents entire per- 
suasion, at least it convicts of emptiness most of 
the arguments with which his adversaries endeavour 
to overwhelm him. He was particularly admirable 
on Monday last, in the house of Signor Federigo 
Ghisilieri ; and what especially pleased me was 
that, before replying to the contrary arguments, 
he amplified and enforced them with new grounds 
of great plausibility, so as to leave his adversaries 
in a more ridiculou3 plight when he afterwards 
overturned them all." 

This entering the lists in the cause of Coperni- 
canism was, to say the least, magnanimous, and 
Galileo was entitled as no other was to appear 
as an advocate; but unfortunately his warm and, 
perhaps, too solicitous efforts in the cause had a 

1 The title Eminence was pot conferred on Cardinals until twelve 
years later. . 



result precisely opposite to the one he intended. 
The fact is, Galileo's too sanguine temperament 
deceived him woefully as to the true course of these 
transactions, as we shall also find to be the case 
in his second and more terrible encounter with the 
Holy Office ; for, a few days after he thought his 
own affairs so satisfactorily settled that he could 
if he chose return to Florence in triumph, a bolt 
shot out of the blue which paralysed him, and 
spread consternation among his friends. Without 
any warning (for such was the manner of the In- 
quisition), on i pth February, the Qualifiers, or 
official experts, of the Holy Office were called on 
for an opinion on the following propositions ex- 
tracted from Galileo's work on the Sun-spots : *- 

(1) The sun is the centre of the world, and, 

therefore, immovable from its place. 

(2) The earth is not the centre of the world, 

and is not immovable, but moves, and 
also with a diurnal motion. 
On the 24th February the Qualifiers reported : 

(1) The first proposition is unanimously de- 

clared to be false and absurd philosophi- 
cally, and formally heretical, inasmuch 
as it expressly contradicts the doctrines 
of Holy Scripture in many passages, 
both if taken in their literal meaning and 
according to the interpretation of the 
Holy Fathers and learned theologians. 

(2) The second proposition is declared unani- 

mously to deserve the like censure (as 
the first) in philosophy, and, as regards 
its theological aspect, to be at least 
erroneous in faith. 


On 25th February, Cardinal Mellini reported 
this opinion to the Holy Office, and, as the result, 
Cardinal Bellarmine was directed "to summon 
before him the said Galileo, and admonish him 
to abandon the said opinion ; and in case of refusal 
the Commissary is to intimate to him, before a 
notary and witnesses, a command to abstain alto- 
gether from teaching or defending the said opinion, 
and even from discussing it ; and if he do not 
acquiesce therein he is to be imprisoned." 

This admonition was administered on the next 
day, as appears from the following minute : 

" Friday, the 26th. At the palace, the usual 
residence of the Lord Cardinal Bellarmine, the said 
Galileo, having been summoned and brought before 
the said Lord Cardinal, was, in presence of the 
Most Revd. Michelangelo Seghizzi, of the order 
of preachers, Commissary - General of the Holy 
Office, warned by the said Lord Cardinal of the 
error of the aforesaid opinion and admonished to 
abandon it. And immediately thereafter before me 
and before witnesses, the Lord Cardinal Bellarmine 
being still present, the said Galileo was by the 
said Commissary commanded and enjoined, in the 
name of his Holiness the Pope, and the whole 
Congregation of the Holy Office, to relinquish 
altogether the said opinion, that the ' sun is the 
centre of the world, and immovable, and that the 
earth moves; nor henceforth to hold, teach, or 
defend it in any way whatsoever, verbally or in 
writing; otherwise proceedings would be taken 
against him in the Holy Office; which injunction 
the said Galileo acquiesced in and promised to obey. 

" Done at Rome, in the palace aforesaid, in the 
presence of Badino Nores, of Nicosia, in the 
Kingdom of Cyprus, and Augustino Mongardo, 


from a place in the abbacy of Rose, in the diocese 
of Politianeti, inmates of the said Cardinal's house, 
witnesses." 1 

Here the process ended so far as Galileo was 
concerned, but it was followed up a few days later 
by an edict prohibiting and suspending certain 
writings, amongst them the book of Copernicus. 
This decree runs as follows : 

"March 3, 1616. The Lord Cardinal Bellar- 
mine having reported that Galileo Galilei, mathe- 
matician, had, in terms of the order of the Holy 
Congregation, been admonished to abandon the 
opinion he has hitherto held, and had acquiesced 
therein ; and the decree of the Congregation of the 
Index having been presented, prohibiting and sus- 
pending respectively the writings of Nicolas 
Copernicus on 'The Revolutions of the Celestial 
Orbs'; of Diego di Zuniga 'On Job'; and of 
Paolo Antonio Foscarini, Carmelite friar ; his Holi- 
ness has ordered this edict of prohibition and sus- 
pension respectively to be published as follows : 
"March 5, 1616 [after preamble]. And 
whereas it has also come to the knowledge of the 
said Congregation that the Pythagorean doctrine 
(which is false and altogether opposed to Holy 
Scripture) of the motion of the earth and the 
quiescence of the sun, which is also taught by 
Nicolas Copernicus in his 'Revolutions of the 
Celestial Orbs/ and by Diego di Zuniga in his 
book 'On Job/ is now being spread abroad and 
accepted by many as may be seen from a certain 
letter of a Carmelite father, wherein he attempts to 
show that the aforesaid doctrine is consonant with 

1 It should be noted that this minute bears no signature, neither of 
Cardinal, Commissary, and witnesses, nor of Galileo. 


truth and is. not opposed to Holy Scripture. 
Therefore, in order that this opinion may not 
insinuate itself any further ^ to the prejudice of 
Catholic truth, the Holy Congregation has decreed 
that the said works of Nicolas Copernicus and 
Diego di Zuniga be suspended until they be cor- 
rected ; that the book of the Carmelite, Foscarini, 
be altogether prohibited and condemned ; and that 
all other books in which the same doctrine is taught 
be likewise prohibited." 1 

It should be noted that the book of Copernicus 
was only suspended until corrected. These "cor- 
rections," which were of the most trivial character, 
were carried out under the supervision of Cardinal 
Gaetani in 1620, after which it would be allowable 
to read the book, and its doctrines could be held by 
the faithful, "ex hypotkesi, and without affirming 
anything." * 

1 The Diego di Zuniga mentioned in this decree was a professor 
in Salamanca, who in 1584 adopted the Copernican theory as not 
opposed to Scripture. Foscarini's letter of 6th January 1615 was 
addressed to the General of his Order, and in it he accepts Galileo's 
discoveries as proof of the truth of the Copernican theory. One 
passage is worth quoting : 

" Holy Church with its visible head, the Pope, assisted by the 
Holy Spirit, cannot err in questions of faith, but it can err in its 
judgments of practical questions, in philosophic speculations, and 
other matters which are not concerned with our salvation." 

This was precisely Galileo's contention throughout all these 

8 They consisted in the omission of a few passages in the preface, 
and in the alteration of certain words in the text, as, notably, the word 
" star " when applied to the earth. Also such words as stated or im- 
plied that the hypothesis was true were altered so as to make it one of 
mathematics pure and simple, and without any pretension to reality. 
As no one cared to bring out an edition of Copernicus in this 
bowdlerised state, his book remained prohibited in Italy for over 
two hundred years. ' 


Galileo remained in Rome for nearly three 
months after the promulgation of the decree of 5th 
March. His enemies spread the report that he had 
been obliged to recant formally and to abjure his 
opinions. It would be easy to show his friends 
how grossly exaggerated was this report; but in 
order the better to confute these calumnies, and 
to guard against them in the future, he obtained 
a paper from Cardinal Bellarmine, stating the facts 
as follows : 

" We, Robert Cardinal Bellarmine, having heard 
that it is calumniously reported that Signor Galileo 
Galilei has in our hand abjured, and has also been 
punished with salutary penance, and being requested 
to state the truth as to this, declare that the said 
Signor Galileo Galilei has not abjured, either in our 
hand or the hand of any other person here in Rome, 
or anywhere else, so far as we know, any opinion 
or doctrine held by him ; neither has any salutary 
penance been imposed upon him, but only the 
declaration made by the Holy Father, and pub- 
lished by the sacred Congregation of the Index, 
has been intimated to him, wherein it is set forth 
that the doctrine attributed to Copernicus that 
the earth moves round the sun, and that the sun 
is stationary in the centre of the world, and does 
not move from east to west is contrary to the 
Holy Scriptures, and therefore cannot be defended 
or held. 

" In witness whereof we have written and sub- 
scribed these presents with our hand this 26th 
day of May 1616." 

We have been careful to give the principal 
documents connected with this momentous process, 
for upon them, and especially upon the unsigned 


minute of 26th February, hinge the charges on 
which Galileo was brought before the Inquisition 
in 1633, and his defence. Von Gebler and other 
critical historians in recent times conclude that the 
minute of 26th February is spurious concocted 
by enemies, and placed among the acts of the 
case with the hope of being useful at some future 
time. Von Gebler says : 

"In common with other critics, we ourselves 
had long been of opinion that this note originated 
not in 1616 but in 1632, in order to legalise the 
trial of Galileo begun in the latter year. But 
after repeatedly and very carefully examining the 
original papers, preserved among the Papal archives, 
we were compelled to acknowledge that the material 
nature of the document entirely excludes the sus- 
picion of a subsequent fabrication. The note was 
not fabricated in 1632, but, probably, in 1616. 
With subtle and perfidious calculation a lie was 
then entered, which was to have the most mo- 
mentous consequences for the great astronomer." 1 

Von Gebler discusses this question at great 
length, but he does not convince us that his 
view is the right one. That the document is not 
a forgery of the year 1616 seems to us sufficiently 
proved by the facts that it lay buried for sixteen 
years, its existence not even hinted at, and that 
it was only accidentally discovered late in 1632, to 
the surprise of every one. Were it a forgery with 
a purpose, its authors would be sure to bring it 
up in the fierce discussions over the comets of 
1618-19, or over Galileo's " II Saggiatore" of 1623, 

1 "Galileo and the Roman Curia," p. 90. 


which contained " heretical" teaching, and which, 
as we shall see, was a b&te noire of the Jesuits, 
or, finally, immediately after the publication of his 
Dialogues early in 1632. That Galileo himself in 
after years said it was a forgery part of a deep- 
laid plan to crush him we can excuse as the 
hasty expression of an outraged man writhing 
under persecution. 

The learned Professor Favaro, who has for the 
last twenty-five years made a study of Galileo's 
life and works, takes the opposite view to Von 
Gebler. He also has very carefully examined 
the Vatican MSS., and can come to no other 
conclusion than that the document in question is 
genuine and bond fide ; that it was drawn up at 
the time, and put in its place, as a record of what 
actually happened, and with no sort of arriere pensde. 

Between these two extreme opinions it seems 
to us that a middle view will more nearly corre- 
spond with the facts, and with the subsequent 
conduct of Galileo and his enemies. We accept 
Professor Favaro's view, but with this qualifica- 
tion, that the document is true to the letter, but 
not to the spirit of the proceedings of 26th 
February. To our mind the admonition by the 
Cardinal was all that was intended (see documents 
above, dated 3rd March and 26th May). The 
further interference of the Commissary - General 
was due to trSp de zele, or fussiness, on his part, 
and may have arisen in this way. Imagine the 
case of a culprit brought up for sentence on his 
first offence before a magistrate and a fussy or over- 
zealous clerk. The culprit, expecting (as we know 


Galileo did) something very mild, is surprised at 
being admonished to abandon his opinions ; he 
gives expression to this surprise by word or look 
seems not to comprehend. "What," he then 
exclaims, "must I abandon them altogether? Can 

I not even dis " " No, no," cuts in the clerk. 

"You are commanded to abstain altogether from 
teaching or defending, and even from discussing 
them in any way whatever, and if you do not 
acquiesce you will be imprisoned." The culprit, 
amazed, says no more, bows, and retires crestfallen, 
noting only the Cardinal's admonition, and disre- 
garding the Commissary's remark altogether, or 
regarding it as no part of the decision, as merely 
a repetition in other and stronger words of the 
Cardinal's simple admonition. 

That this is the view which Cardinal Bellarmine 
and the Holy Office took of the proceedings is clear 
from the wording of the documents dated 26th May 
and 3rd March, in which the interpolation of the 
Commissary-General is ignored ; and that it is the 
view which Galileo took, his after conduct will 
show. Then, the facts that his writings are not 
mentioned in the decree of 5th March, and that 
the book of Copernicus is only suspended pending 
correction, go to show that the Copernican doctrines 
might still be held and discussed in a hypothetical 
way, and by Galileo as well as by others. In 
fact, it was so understood at the time, and the 
trivial alterations afterwards made in the book of 
Copernicus (as above stated) confirmed this idea, 1 

Galileo having taken his admonition was ad- 

1 See more on this subject p, 275 infra. 


mitted to an audience of the Pope, Paul V., on 
nth March, which lasted three-quarters of an 
hour. He took occasion to refer to the events 
just concluded, and expressed his fears of never- 
ending persecution; but Paul V. consoled him 
with the assurance that he need have no fear ; that 
he was held in so much esteem by himself and the 
whole Congregation, that they would not listen to 
any calumnies ; and that, as long as he occupied 
the chair of St Peter, Galileo might rest assured 
that he was safe from all danger, 

On the eve of Galileo's departure from Rome, 
Cardinal del Monte wrote to the Grand Duke 
"to bear witness that he was leaving with the 
best reputation, and the approval of all who have 
had transactions with him, for it has been made 
manifest how unjust have been the calumnies of 
his enemies/' 1 However, the Grand Duke's 
Ambassador, Guicciardini, told a different story, 
and, perhaps, a truer one. All along he had tried 
to get Galileo recalled to Florence ; his last letter 
of 1 3th May may be cited as a specimen of his 
previous despatches. 

"Galileo," he says, " seems disposed to emulate 
the monks in obstinacy, and to contend with 
personages whom you cannot attack without ruin 
to yourself. It may any moment be heard in 
Florence that he has stumbled into some abyss 
or other. However, the heat will probably drive 
him from Rome before long, and that will be the 
best thing that can happen to him." 

Cosimo IL, alarmed by these gloomy reports 
1 The letter is dated 4th June 1616. 

i6i7] ON THE TIDES 171 

of his ambassador, at last issued orders for Galileo's 
return, and on 23rd May Picchena wrote : 

" You have had enough of monkish persecutions 
and ought to know by this what the flavour of them 
is. His Highness fears that your longer stay in 
Rome may involve you in fresh difficulties, and 
would therefore be glad if (as you have so 
far come honourably out of the affair) you would 
not tease the sleeping dog any more, and would 
return here as soon as possible. There are rumours 
flying about which we do not like, and the monks 
are all powerful. I, your servant, must not fail 
to warn you, and to inform you, as in duty bound, 
of the wishes of our Master, wherewith I kiss your 

Galileo complied with this order with the least 
possible delay, and set out on his homeward 
journey on 4th June 1616. 

Amidst all the cares and worries of this visit 
Galileo's teeming mind was busy, as always, with 
abstruse questions of science. He had not been 
many days in Rome when a suggestion from 
Cardinal Orsini was enough to start him on a 
treatise on the Flux and Reflux of the Tides, written, 
as was customary in those days, in the form of a 
letter to the Cardinal, and dated 8th January 1616. 
We have seen from his letter to Vinta, of 7th May 
1610, in which he enumerates his contemplated 
works, that a treatise on the Tides was one of 
them. Galileo's theory is that the tides are the 
visible effects of the terrestrial double movement, 
since they are the combined result of (i) the earth's 
daily rotation, and (2) the inequality of the absolute 
velocities through space of the various parts of the 


earth's surface. We now know this to be erroneous, 
but it required a farther advance in the science of 
motion than had been obtained even at a much 
later date to point out its insufficiency. 

The problem of the tides had been from the 
earliest ages one of the most difficult, and the 
solutions advanced by different enquirers show that 
it long deserved the name given to it "the grave 
of human curiosity." Some supposed the rise of 
the waters to be due to the influx of rivers into the 
sea ; others compared the earth to a huge animal, 
whose respiration caused the tides ; a third theory 
supposed the existence of subterraneous fires which 
periodically made the sea to boil up ; while others 
again attributed this boiling effect to changes of 
temperature in the sun and moon, or to variations 
in the amount of their light. 

Galileo's ideas on the subject are given at great 
length in his treatise, and are developed and re- 
inforced in his Dialogues on the Two Systems of 
the World, where they occupy the whole of the 
fourth "Day." 

Almost as soon as he had discovered the moons 
of Jupiter in 1610, Galileo began a work the 
difficulty and fatigue of which he has himself 
indicated by comparing it with the labours of Atlas. 
It was a series of observations on the satellites with 
a view of drawing up tables so as to be able to 
predict all particulars of their situations, relations, 
and eclipses ; and thus to have the means of 
determining at any hour of the night the longitude 
of the place of observation. In the midst of 
his numerous occupations and annoyances of all 


sorts, he steadily worked at this laborious 
task. 1 

After six years' observation and calculation of 
Jupiter's satellites, and confident of the practica- 
bility of his method, Galileo in 1616 opened a 
correspondence on the subject with the Court of 
Spain. 2 The reader will understand how the 
satellites were to be used, if their movements 
could be so nicely ascertained as to enable 
Galileo at Florence to predict the exact times 
at which any remarkable configurations, such as 
an eclipse, would occur. A mariner, who should 
observe the same eclipse and compare the local time 
(which he might know by setting his watch by 
the sun on the previous noon) with the time 
mentioned in the tables, would, from the difference 
between the two, have data for calculating his 
position. Thus, as the earth rotates through 
360 of longitude in 24 hours, or 15 per hour, 
the difference between the two times multiplied 

1 A ready method of finding longitudes at sea had long been an 
object of search with all the maritime powers of Europe. In 1598 
the Spanish Government offered a prize of 1000 crowns for the 
discovery of such a method. The Dutch followed the example of 
Philip III. of Spain ; the French Government followed with a prize of 
100,000 livres ; and the French Academy established an annual 
prize for those who made the most useful discoveries connected with 
the subject. In 1714 the English Parliament appointed a committee 
to consider the question, when an Act was passed gran ting ^10,000 for 
a method of finding the longitude to a degree, or 60 geographical 
miles ; i 5,000, to 40 miles ; and ^20,000, to 30 miles. At length, 
in 1736, the problem was solved in the ship's chronometer of John 
Harrison, a village carpenter of Faulby, Yorkshire, which did not vary 
two minutes in the course of a year. 

2 In 1612 Galileo first announced his method to the Spanish 
Government, through the medium of the Tuscan Ambassador, but 
no details or explanations were then given. 


by 15 will give the degrees of longitude by 
which the ship is distant from the meridian of 

Our moon had already been used for the 
same purpose; it changes its position amongst 
the stars continuously, and if at specified times 
throughout the day that position can be predicted, 
it is available as a signal of the exact time at 
Florence, or wherever the tables are calculated 
for. Using his watch as already explained, the 
mariner would then be able to determine his 
longitude. But in the beginning of the seven- 
teenth century, tables predicting the position of 
the moon could only have been very rough. 
And its very proximity to the earth is a dis- 
advantage; for an observer on the high seas 
would get a slightly different view of it from 
that expected at Florence, and this apparent 
difference in the moon's position amongst the 
stars, as seen from the two different places, 
would have to be allowed for. 

This complication would be avoided if Jupiter 
were made use of as a time-recorder instead of 
the moon. The great distance of Jupiter, the 
frequency of the eclipses (more than 1000 yearly), 
and (it was expected) their suddenness, seemed 
to promise success to Galileo's method. It was, 
however, beset by practical difficulties. First, 
there was the difficulty of observing such small 
objects as Jupiter's moons from the deck of a 
ship ; and secondly and greater, accurate time- 
keepers were necessary, but were not available ; 
for, although we have just spoken of watches. 


the watches and clocks of those days were not 
such as could be relied on even for the few 
hours between the time of observing the sun 
at noon and the subsequent observation of 

Galileo thoroughly appreciated these difficulties, 
and to obviate the first he proposed to use a 
binocular telescope with a magnifying power of 
10 diameters. This he called the Celatone or 
Testiera> as the apparatus resembled a diving- 
helmet with telescopes fixed in the apertures for 
the eyes. 1 He also had made in the arsenal at 
Pisa a kind of boat or chair, floating in another 
boat filled with water or oil, in which the observer 
would be protected from all motion. 2 To remedy 
the second difficulty he had hopes of utilising his 
early observations on the pendulum and applying 
it as a measurer of time. But it was many years 

1 The above reference to the Celatone is based on a letter of 
Galileo to Orso d'Eki, without date but circa June 1617. The 
passage is vague and evidently with a purpose, as he wished the 
" invention" to be kept secret. Professor Favaro has since drawn my 
attention to another of Galileo's letters, dated 6th June 1637, in which 
we find the apparatus for the first time clearly described. " I made," 
he says, " for the use of our navy a kind of cap, fitted to the head of 
the observer, and supporting a telescope in such a way that it always 
points in the same direction as the tree eye, so that an object viewed 
by the latter is also seen by the other eye through the telescope. A 
similar apparatus could be made and fixed on the shoulders and chest 
of the observer, to support a telescope of a power sufficient to show 
the satellites of Jupiter, and adjustable as in the case of the Celatone. 
When, then, the free eye is turned towards Jupiter the other eye sees 
through the telescope not only the planet but its satellites." From 
this it is clear that Galileo did not propose a binocular telescope as 
has hitherto been supposed, but simply a new way of using an ordinary 

2 Galileo's letter to Picchena, 22nd March 1617. In this way he 
is said to have made satisfactory observations in the harbour of 
Leghorn, while the ship was tossed about by a strong wind. 


later before steps were taken to give his ideas a 
practical form. 

During his visit to Rome (in 1616) Galileo 
disclosed his longitude proposals to the Conte 
di Lemos, the Spanish Viceroy of Naples, who 
had been President of the Council of the Spanish 
Indies, and was fully aware of the importance of 
the matter. Negotiations were opened with the 
Spanish Minister at Rome, and the Grand Duke 
of Tuscany, Cosimo II., instructed his ambassador 
at Madrid to conduct the business with the 
Spanish Court. Galileo entered warmly into 
these negotiations, as may be gathered from the 
following extract from a letter to the Tuscan 
Minister in Spain. 

"Your Excellency may well believe that if 
this were an undertaking which I could conclude 
by myself, I would never have gone about 
begging favours from others. But in my study 
there are neither seas, nor Indies, nor islands, 
ports, shoals, and ships, for which reason I am 
compelled to share the enterprise with great 
personages, and to fatigue myself to procure the 
acceptance of that which ought with eagerness 
to be asked of me. But I console myself with 
the reflection that I am not singular in this, since 
it commonly happens that, with the exception of 
a little reputation (and that too often obscured 
and blackened by envy), the least part of the 
advantage falls to the share of inventors of things 
which bring gain (in honours and riches) to 
others. However, I will never cease to do 
everything in my power to forward this matter. 
I am ready to leave here all my comforts, 
country, family, friends, and to cross over into 


Spain, to stay as long as I may be wanted in 
Seville, or Lisbon, or wherever it may be 
convenient, in order to implant the knowledge of 
my method, provided only that due assistance 
and diligence be not wanting on the part of 
those who are to receive it." 

But he could not, with all his enthusiasm, 
bring the Spanish Court to a decision. His 
proposals were discussed in Council, favourable 
reports were made to the King, but his Majesty 
could not make up his mind to spend money on 
experiments which he thought might prove as 
fallacious as others that had been tried before 
with the same object. The negotiation dragged 
on during 1617 and part of 1618 and then 
languished, and, although occasionally renewed 
during the next ten or twelve years (in 1620, 
1629, and 1632), was never brought to a satisfactory 

Galileo's ' disappointment was in some degree 
mitigated later on by his own Sovereign taking 
up the method for use in the Tuscan Navy. Its 
application, however, has proved to be beset with 
so many difficulties that the method has fallen 
into disuse. The unsteadiness of the observer 
at sea cannot be overcome, and is more serious 
in an observation of the required nature than in 
the measurement of the moon's distance from a 
star. Accordingly the method is now one of 
historic interest only. 




FOR a long time after his return to Florence in 
June 1616, Galileo's health had been very indifferent. 
A complication of his old maladies, aggravated by 
long fits of hypochondria, left him little time or 
taste for work, and sadly interrupted his corre- 
spondence. His old friend Sagredo often advised 
him to take his ease and be content with the 
laurels he had already won. " Philosophise," he 
used to say, "comfortably in your bed and 
leave the stars alone. Let fools be fools, let the 
ignorant plume themselves on their ignorance. 
Why should you court martyrdom for the sake of 
winning them from their folly? It is not given 
to every one to be of the number of the elect. I 
believe the universe was made for my service, not 
I for the universe. Live as I do and you will be 
happy." This, indeed, was the burden of Sagredo's 
letters from the time his friend quitted Padua in 
1610 up to his own death on 5th March 1620. 

But Galileo had not the epicurean temperament 
of his friend. Speculation and experiment were as 
necessary to him as food and air ; yet from these 


1617-1624] DESPONDENCY 179 

he was now practically debarred by the Papal pro- 
hibition of 26th February. How could he resume 
his old work, or begin any new one ? The Coperni- 
can theory of the world was the basis of all his 
work. Its acceptance and application were for- 
bidden him, and the general permission to employ 
it as a working hypothesis was a mockery. Can 
we wonder then at the fits of melancholy which 
frequently oppressed him. Yet inaction to a man 
of his temperament was intolerable; he must be 
doing something ; he was fond of gardening, but 
he could not be always digging, and weeding, and 
pruning. He must be doing something else; he 
could not write for publication, but he could at least 
commune with his intimate friends ; and so, for some 
years he poured out his thoughts in long private 
letters, copies of which were circulated amongst the 
learned men of Europe. Unfortunately, few of 
these are now extant ; but amongst these few there 
is one which deserves notice, as it shows how in- 
tolerable the writer felt his position to be. It is 
also interesting as a specimen of the keen sarcasm 
of which he was a master. During his stay at 
Rome, as we have seen, he wrote a treatise on the 
tides. Now, on 23rd May 1618, he sent .a copy of 
this to the Archduke Leopold of Austria; but as 
since it was written the proceedings culminating in 
the decree of 5th March 1616 had taken place, 
Galileo added the following accompaniment : 

"With this I send a treatise on the causes of 
the tides, which I wrote more than two years ago, 
at the suggestion of his Reverence Cardinal Orsini 
in Rome, and at the time when the theologians 


were thinking of prohibiting the book of Copernicus 
and the doctrine enunciated therein of the motion 
of the earth, which I held to be true until it pleased 
those gentlemen to prohibit the work and to declare 
that opinion to be false and contrary to Scripture. 
Now, knowing as I do that it behoves us to obey 
the decisions of the authorities and to believe them, 
since they are guided by a higher insight than any 
to which my humble mind can of itself attain, I 
consider this treatise which I send you merely to 
be a poetical conceit or a dream, and desire that 
your Highness may take it as such, inasmuch as it 
is based on the double motion of the earth, and, 
indeed, contains one of the arguments which I have 
adduced in confirmation of it. But even poets 
sometimes attach a value to one or other of their 
fantasies, and I likewise attach some value to this 
fancy of mine. Now, having written this treatise 
and having shown it to the Cardinal above 
mentioned and a few others, I have also let a few 
exalted personages have copies, in order that, 
in case any one not belonging to our Church should 
try to appropriate my curious fancy (as has 
happened to me with many of my discoveries), 
these personages, being above all suspicion, may be 
able to bear witness that it was I who first dreamed 
of this chimera. What I now send is but a fugitive 
performance. It was written in haste and in the 
expectation that the work of Copernicus would not 
be condemned as erroneous eighty years after its 
publication, I had intended at my convenience and 
in quiet to have gone more particularly into this 
subject, to have added more proofs, to have 
arranged the whole anew, and to have put it into 
a better form. But a voice from heaven has 
aroused me and dissolved all my confused and 
tangled fantasies in mist! May therefore your 
Highness graciously accept it, ill-arranged as it is ; 

1 624] THE COMETS OF 1618 181 

and if Divine love ever grants that I may be in a 
position to exert myself a little, your Highness may 
expect something more solid and real from me." 

In August 1618, three comets appeared in the 
heavens, and the brilliant one in the constellation 
of the Scorpion one of the most splendid of 
modern times especially attracted the attention 
of astronomers. Although this was visible until 
January 1619, Galileo had little opportunity of 
observing it, as he was confined to bed nearly the 
whole time by severe illness. 1 However, we may 
suppose with Viviani that he was able to observe a 
little, but, certainly, he reflected much, and, as soon 
as he was able, he communicated his views to his 
friends, amongst others to the above-mentioned 
Archduke Leopold, who, being in Florence on a 
visit, came to see him. 

His views were published about the middle of 
1619, through the medium of Mario Guiducci, a 
Florentine disciple. 2 He did not consider comets to 
be really heavenly bodies, analogous to the planets 
as was currently supposed, but only atmospheric 
phenomena columns of vapour which rise from the 
earth to a great height, far beyond the moon, and be- 
come temporarily visible by refraction of the sun's 
rays. In fact, he classed comets in the same category 
as rainbows and mock suns. Referring to some 
proposed parallax measurements of the comets, 

1 During great part of the years 1617 and 1618, Galileo was ill or 
ailing. In June 1618 he made a pilgrimage to Loreto, "The Mecca 
of Christendom," in the hope that a change of air and habits might 
free him from the fevers which molested him- 

2 "Discorso delle Comete di Mario Guiducci," etc., Florence, 


he pointed out the difference in this respect 
between a fixed object, the distance of which 
may be calculated by two angular observations 
at a known distance apart, and atmospheric 
appearances like rainbows which are simul- 
taneously formed in different drops of water 
for each spectator, so that two observers in 
different places are, in fact, viewing different 
objects. He then warns astronomers not to 
engage with too much warmth in a discussion 
on the distance of comets before they assure 
themselves to which of these two classes of 
phenomena they are to be referred. The 
remark is in itself perfectly just, although the 
opinion which occasioned it is now known to 
be erroneous ; but it is questionable whether the 
few observations which up to that time had been 
made upon comets were sufficient to justify the 
bitter censures which have been cast on Galileo 
on account of it. Indeed, the same opinion was 
held for a time by Cassini, the celebrated 
astronomer of the Paris Observatory, many years 
after Galileo, and when the science was con- 
siderably more advanced ; and even Newton 
did not consider it beneath notice, for in his 
"Principia" he takes pains to show on what 
grounds it is untenable. 

In the course of Guiducci's essay, some opinions 
of the Jesuit father, Orazio Grassi (in a public 
discussion on the comets at the Collegio Romano), 
were so indiscreetly attacked as to raise the ire 
of the whole Jesuit's College at Rome. Grassi, 
under the pseudonym of Lotario Sarsi, published 


an onslaught on Galileo's cometary theory in a 
book called "The Astronomical and Philosophical 
Balance" (1619) a violent pamphlet full of abuse 
of Galileo and his school. 1 Friends, like Prince 
Cesi, and Mgrs. Ciampoli and Cesarini, now 
advised that the master himself should take up 
the fight ; but ill-health and caution, owing to the 
troubled state of the religious and political horizons, 
prevented the appearance of his reply for three 
years. At length, in October 1622, he sent the 
MS. of this celebrated work, " II Saggiatore *' 
(The Assayer), to Mgn Cesarini in Rome, and 
for five months it passed from hand to hand 
among the members of the Accademia dei Lincei, 
who examined it carefully and (with the author's 
consent) altered some passages which might 
possibly have given a handle to his enemies. 
The Papal Imprimatur was granted 2nd February 
1623, on the report of Father Niccolo Riccardi, 
Examiner, who was formerly a pupil of Galileo, 
and of whom we shall hear a great deal in the 
sequel. This report was as follows: 

"By command of the Master of the Palace, 
I have read the work f II Saggiatore/ and not 
only have I detected nothing in it which is contrary 

1 The reader will have observed that, so far, hardly one of 
Galileo's discoveries, or of his published opinions, whether correct or 
incorrect, has wanted antagonists and detractors ; and so we shall 
find it to the end. The case is probably unique in history, and rightly 
did Byron sing of " The starry Galileo with his Woes," for never was 
a man so persecuted for fifty out of the seventy-eight years of his busy 
life* A French biographer (Parchappe) justly laments "the loss to 
science in the enormous expenditure of energy and time consumed in 
defending himself and his teaching against the incredible rage of his 
enemies in struggles without end." "Galilee, sa Vie," etc, Paris, 
1866, p. 79. 


to good morals, or deviates from the Divine Truth 
of our religion, but I have found in it such beautiful 
and manifold observations on natural philosophy 
that I think our age will not have to boast merely 
of having been the inheritor of the labours of 
earlier philosophers, but also of having been the 
discoverer of many secrets of nature which they 
were not able to penetrate, thanks to the subtle 
and solid researches of the author whose con- 
temporary I think myself happy to be." 

While the work was in the press, an event 
occurred which seemed likely to produce a change 
for the better in Galileo's relations with Rome. 
On 8th July 1623, Gregory XV. succumbed to age 
and infirmity in the second year of his pontificate ; 
and the man, who at the age of fifty-five succeeded 
him (elected 8th August 1623), was Cardinal 
Maffeo Barberini, now Pope Urban VII L 
Galileo placed great hopes for the progress of 
science in general, and for, at least, toleration of 
the Copernican doctrine, on this election ; and 
to all appearances he was justified in doing so. 
Not only was Urban VIII. a refreshing contrast 
to his immediate predecessors who cared little for 
art or science, but, as Cardinal, he had for many 
years entertained a great friendship for Galileo, 
as many letters of his still extant show. Thus, 
writing from Bologna, 5th June 1612, on receipt of 
a copy of the work on Floating Bodies, he says : 

"I have received your treatise on various 
scientific questions which have been raised during 
my stay here, and shall read them with great 
pleasure, both to confirm myself in my opinions 


which agree with yours, and to enjoy with the rest 
of the world the fruits of your rare intellect/' 

Another letter of 2Oth April 1613, after the 
work on Sun-spots had appeared, may be 
quoted : 

1 * Your printed letters to Welser have reached 
me, and are very welcome. I shall not fail to 
read them with pleasure again and again as they 
deserve. This is not a book which will be allowed 
to stand idly among others. It is the only one 
which can induce me to withdraw for a few hours 
from my official duties to devote myself to its 
perusal, and to the observation of the planets of 
which it treats if the telescopes we have here 
are fit for it. Meanwhile I thank you very much 
for your remembrance of me, and beg you not 
to forget the high opinion which I entertain for 
a mind so extraordinarily gifted as yours." 

The Cardinal had not confined himself to mere 
assurances of esteem and friendship in his letters, 
but had shown them in his acts. Thus, in the 
troublous times in 1615-16, his influence with 
Pope Paul V. greatly helped Galileo to extricate 
himself from his difficulties. 

In 1620, Barberini gave another and a really 
enthusiastic proof of his regard. He celebrated 
Galileo's discoveries in some elegant verses (in 
which astronomy was allied with morality) and 
sent them with the following letter, dated 2 8th 
August : 

"The esteem, which I always entertain for 
yourself and for your great merits, has given 
occasion to the enclosed verses. If not worthy 


of you they will serve at any rate as a proof of 
my affection ; while I purpose to add lustre to 
my poetry by coupling it with your renowned 
name. Without wasting words in further apologies, 
I beg you to receive with favour this small proof 
of my great esteem." 

After much delay in the printing, "II Saggiatore" 
appeared at the end of October 1623, with a 
dedication to Pope Urban VIIL, and under the 
auspices of the Accademia dei Lincei. This cele- 
brated work is a masterpiece of ingenuity, for the 
author not only dexterously avoids the snares laid 
for him by Father Grass! and his supporters, but 
brings defeat and ridicule upon them at every 
turn. All this is done in so sparkling a style, 
and the reasoning, and counter refutations are 
so convincing, that "II Saggiatore" deserves its 
reputation as a model of dialectic skill, and an 
ornament of classical Italian literature. 

The book was a great success, and, of course, 
intensified the bitterness of the Jesuitical party; 
so much so that the General of the Order forbade, 
under severe penalties, the members to speak of 
it even among themselves. It is important to 
note that the Pope was delighted with it, and 
had it read aloud to him at table. 

Early in 1625, the book was denounced 
anonymously to the Inquisition as a veiled 
defence of the Copernican doctrines, and a move- 
ment was begun to prohibit it, or, at least, to 
have it "corrected"; but the attempt failed, and 
only brought discredit upon the agitators. Father 
Guevara, General of the Theatines, to whom it 

1624] "IL SAGGIATORE" 187 

was submitted for examination, reported most 
favourably of it, and went so far as to say that, 
even if the doctrine of the earth's motion had 
been maintained, it would not have appeared 
to him a sufficient reason for condemning the 

One or two extracts will be interesting. As 
a specimen of keen cutting banter the following 
is admirable. Sarsi had quoted a story from Suidas 
(in support of his argument that motion always 
produces heat) to the effect that the Babylonians 
used to cook their eggs by whirling them in a 
sling. To this Galileo replied : 

" I cannot refrain from marvelling that Sarsi 
will persist in proving to me, by authorities, that 
which at any moment I can bring to the test of 
experiment We examine witnesses in things 
which are doubtful, past, and not permanent, but 
not in those things which are done in our own 
presence. If discussing a difficult problem were 
like carrying a weight, since several horses will 
carry more sacks of corn than one alone will, I 
would agree that many reasoners avail more than 
one ; but discoursing is like coursing, and not like 
carrying, and one barb by himself will run farther 
than a hundred Friesland horses. When Sarsi 
brings up such a multitude of authors, it does not 
seem to me that he in the least degree strengthens 
his own conclusions, but he ennobles the cause of 
Signor Mario and myself, by showing that we 
reason better than many men of established re- 
putation. If Sarsi insists that I must believe, 
on Suidas's credit, that the Babylonians cooked 
eggs by swiftly whirling them in a sling, I will 
believe it ; but I must say, that the cause of such 
an effect is very remote from that to which it is. 


attributed, and to find the true cause I shall reason 
thus. If an effect does not follow with us which 
followed with others at another time, it is because, 
in our experiment, something is wanting which was 
the cause of the former success ; and if only one 
thing is wanting to us, that one thing is the true 
cause. Now we have eggs, and slings, and strong 
men to whirl them, and yet they will not become 
cooked ; nay, if they were hot at first they more 
quickly become cold ; and since nothing is wanting 
to us but to be Babylonians, it follows that being 
Babylonians is the true cause why the eggs became 
cooked, and not the friction of the air, which 
is what I wish to prove. Is it possible that in 
travelling post, Sarsi has never noticed what fresh- 
ness is occasioned on the face by the continual 
change of air ? and if he has felt it, will he rather 
trust the relation by others of what was done two 
thousand years ago at Babylon, than what he can 
at this moment verify in his own person? I, at 
least, will not be so wilfully wrong, and so un- 
grateful to nature and to God, that having been 
gifted with sense and language I should voluntarily 
set less value on such great endowments than 
on the fallacies of a fellow-man, and blindly and 
blunderingly believe whatever I hear, and barter 
the freedom of my intellect for slavery to one as 
liable to error as myself." 

Our next extract is a good sample of Galileo's 
metaphysics, in which may be observed the germ of 
a theory closely allied to that which was afterwards 
developed by Locke and Berkeley. 

" I have now only to fulfil my promise of declar- 
ing my opinions on the proposition that motion is 
the cause of heat, and to explain in what manner it 
appears to me that it may be true. But I must first 


make some remarks on that which we call heat, 
since I strongly suspect that a notion of it prevails 
which is very remote from the truth; for it is be- 
lieved that there is a true accident, affection, or 
quality, really inherent in the substance by which 
we feel ourselves heated. This much I have to say, 
that as soon as I form a conception of a material or 
corporeal substance, I simultaneously feel the 
necessity of conceiving that it has its boundaries, 
and is of some shape or other; that, relatively to 
others, it is great or small ; that it is in this or that 
place, in this or that time ; that it is in motion, or at 
rest ; that it touches, or does not touch another body ; 
that it is unique, rare, or common ; nor can I, by any 
act of the imagination, disjoin it from these qualities ; 
but I do not find myself absolutely compelled to 
apprehend it as necessarily accompanied by such 
conditions as that it must be white or red, bitter or 
sweet, sonorous or silent, smelling sweetly or dis- 
agreeably ; and if the senses had not pointed out 
these qualities, it is probable that language and 
imagination alone could never have arrived at them. 
Therefore, I am inclined to think that these tastes, 
smells, colours, etc., with regard to the object in 
which they appear to reside, are nothing more than 
mere names, and exist only in the sensitive body ; 
insomuch that when the living creature is removed 
all these qualities are carried off and annihilated ; 
although we have imposed particular names upon 
them (different from those other and real accidents), 
and would fain persuade ourselves that they truly 
and in fact exist. But I do not believe that there 
exists anything in external bodies for exciting tastes, 
smells, and sounds, but size, shape, quantity, and 
motion, swift or slow; and if ears, tongues, and 
noses were removed, I am of opinion that shape, 
quantity, and motion would remain, but there would 
be an end of smells, tastes, and sounds, which, 


abstractedly from the living creature, I take to be 
mere words." 

As we are now approaching the great crisis of 
Galileo's public life, it will be convenient to pause 
and take a glance at his family affairs. We have 
seen (p. 73) that he was never married, but that he 
had by the Venetian, Marina Gamba, three children 
Virginia, Livia, and Vincenzio. These children 
were brought up with the mother in Padua, and in 
a separate establishment from that occupied by the 
father in Via Vignali. 

It would appear that when Galileo quitted Padua 
in the autumn of 1610, he took the two girls with 
him to Florence, and placed them under the care of 
his brother-in-law, Landucci ; Vincenzio, being then 
only four years old, was left behind with his mother 
until October 1612, when he too was brought to 
Florence. Shortly afterwards, Marina married a well- 
to-do man in her own sphere, one Giovanni Bartoluzzi. 
This step appears to have been taken with Galileo's 
approval, judging from the respectful and friendly 
tone of the only letter of Bartoluzzi (i7th August 
1619) found amongst Galileo's papers. It appears 
from this letter, and from two others written by 
Liceti, 3ist December 1610, and Pignoria, 25th 
January 1613, that Galileo behaved with great 
liberality to Marina and her husband. 

In March 1610, before his final departure from 
Padua, he had the intention of placing his elder 
daughter as a boarder in the convent of the Nun- 
ziatina, Florence ; but, although all the preliminaries 
were settled, the project, for some unknown reason, 


was not carried out. What to do with the girls 
was now become a serious question. Their taint 
of birth was in painful contrast to the honoured 
name of his own noble family, as his mother, in her 
frequent and " terrible " tempers, did not fail to 
remind him. His means, generally as we have 
seen insufficient for his wants and never too large, 
did not hold out the hope of being able to make 
them independent, or to settle them suitably in 
marriage. In these circumstances he resolved, 
while they were yet young, and before they could 
acquire a taste for the world, to place them both in 
a convent for life. In November 1611, he took 
steps to carry out this resolution, but met with many 
difficulties. He did not wish that the children 
should be separated, but there was a strict rule 
against sisters taking the veil in the same convent 
Then, there was the further difficulty of the girls 
being much under the canonical age of full sixteen 
Virginia, the elder, being only eleven. However, 
after long negotiations, and finally through the 
influence of Cardinal Bandini, the necessary licences 
were obtained, and in October 1613 the two girls 
were placed in the Convent of San Matteo, Arcetri, 
near Florence, as a preparatory step to their novi- 
tiate and final profession. In July 1614 they were 
entered as novices of the Order. The Mother 
Abbess of the time was a sister of the Secretary 
Vinta, whose name has often occurred in these 
pages. From the first the good Lodovica Vinta 
took a kindly interest in the poor children ; and at 
her suggestion the feasting usual on taking the veil 
was dispensed with. "It would be better," she said, 


" in every way for the ceremony to take place quietly, 
and the money will be far better employed in adding 
to the girls' little comforts in the convent than in 
regaling friends and relations/' Finally, Virginia 
became a professed nun on 4th October 1616, 
under the name of Suor Maria Celeste ; and Livia 
on 28th October 1617, under the name of Suor 
Arcangela ; and here we shall leave them for awhile. 

After the death of Filippo Salviati, on 22nd 
March 1614, Galileo appears to have given up 
the villa near Signa, and to have had no settled 
home of his own for the next three years. He 
probably had a pied-a-terre in his mother's house, 
where, owing to her terrible tempers and his own 
frequent illnesses, his lot was not a happy one. 

On 1 5th August 1617, he rented the villa of 
Lorenzo Segni on the Bellosguardo Hill outside 
Florence, and here he lived for the next fourteen 
years. Perched upon a hill it commanded most 
lovely views of the city and the silvery Arno at 
its foot, with the far-famed Fiesole beyond, and 
of beautiful country all round. 

" From Tuscan Bellosguardo, 
Where Galileo stood at nights to take 
The vision of the stars, we have found it hard, 
Gazing upon the earth and heavens, to make 
A choice of beauty." 


Two hundred years after, the villa was for a 
time (circa 1810) the residence of another famous 
Italian, Ugo Foscolo, the poet and patriot-soldier 
of the stirring times in Italy during the Napoleonic 
period. In 1835, the then owner, Amerigo degli 


Albizzi, erected on the north-west front of the house 
two white marble tablets (each surmounted by a 
white marble bust) with long inscriptions com- 
memorative of these two great men. The bust 
of our philosopher, showing well his peculiar nose, 
is the work of the Florentine sculptor Emilio 
Demi ; and the inscription is from the pen of 
Vincenzio Antinori, then Director of the Museum 
of Natural History, Florence. 1 

For nearly seven years after taking the veil we 
lose sight of Galileo's daughters. We left them 
as children of sixteen ; we are now to meet them 
as women. Sister Arcangela, the younger, we 
shall not like ; but Virginia, or Sister Maria 
Celeste, as we must henceforth call her, we shall 
learn to love. All we know of this charming 
personality is told in her letters to her father. 
The first is dated loth May 1623, but Professor 
Favaro thinks there must have been many previous 
ones which are now lost. However this may be, 
those that remain, one hundred and twenty-four 
in number, show that there was a close intimacy 
and affection between father and daughter, and 
that these relations grew in intensity with the 
daughter's maturing years. If they did not write 
they must have often met, for Galileo's house at 
Bellosguardo was a pleasant half-hour's walk 
along a charming road from the convent of San 

1 For the inscription see Albert's ed. of Galileo's works, vol. xv. 
p. 394. The house is now known as Villa POmbrellino, and is occupied 
by the Russian General, Alexis Zouboflj who kindly allows visitors 
to see these interesting memorials. The villa is entered from the 
Piazza Bellosguardo, where one sees on a house in front a marble 
slab intimating that Garibaldi and Mario lived there. 



Matteo. In no other way than on the supposition 
of a previous intimacy of a close personal kind 
can we account for the affection which bursts 
forth in the first letter we possess, and overflows 
through all of them to the end. This affection 
must have been, as indeed we shall see it was, 
a great comfort and consolation to Galileo, sorely 
tried as he was by frequent illness, by the worries 
and ingratitude of all the rest of his family, and 
by the persecution of the outside world. 

His letters to his daughter, though we know 
that she kept them, and was in the habit of 
re-reading them during such leisure moments as 
her duties left to her, have unfortunately dis- 
appeared. It is probable that these letters so 
treasured by the daughter were destroyed at her 
death, lest the convent should be compromised 
by their presence among its archives an action 
which, however much we may regret it, we 
cannot blame, as we must remember that when 
Maria Celeste died in 1634 her father was a 
prisoner of the Inquisition, vehemently suspected 
of heresy. 

We can, however, generally guess the contents 
of these lost letters, by the answers, which, thanks 
to her father's loving care, have been preserved 
to us. In these, Sister Maria Celeste emerges 
from behind the convent grating ; she lifts the 
veil which envelops her, and shows us a woman's 
heart full of filial tenderness, of self-abasement, 
and of interest in some things of that world she 
had renounced in her childhood. We see this 
heart of hers often pierced with sorrow, and always 


divided between love and fear love for her father, 
and fear of impending evil to him. 

Besides the father-worship which glows in every 
page, these letters bear evidence throughout of 
sound sense and sober judgment, joined to a 
simple piety. There is not a trace of mysticism 
in them ; there is no mention of minute practices 
of devotion ; she does not pass her nights in the 
chapel, kneeling on cold stones and expecting 
visions ; she goes to bed like a sensible woman, 
and takes her seven hours' sleep ; she regrets 
sometimes that her constitution should require so 
much sleep, but only because she would like 
better to sit up and write long letters to her 
" Dearest Lord and Father." Of her Heavenly 
Father she discourses much ; of the Virgin seldom ; 
and we hear of no patron saint. The nuns, she 
tells us, have each their patron saint their Devote 
to whom they tell all their little joys and sorrows ; 
but she has her father to confide in and therefore 
wants no Devoto. 

Around this loving and lovable nun the other 
sisters stand a group of shadows with a name 
attached to each. Some flit by, once mentioned 
sisters these, but not friends ; a few come before 
us more often, Sister Luisa Bocchineri in particular, 
who was Maria Celeste's bosom friend, and a sister 
of her brother Vincenzio's future wife. Her own 
sister Livia appears as little more than a shadow, 
and what we see of her inclines us, perhaps, to 
some pity, but to little love. Her disposition seems 
to have been decidedly selfish, and her sister had 
to give up to her a great deal for the sake of peace. 


" As Sister Arcangela's disposition/' she writes, 
"is very different from mine, being rather odd and 
whimsical, it is better for me to give up to her in 
many things, in order to preserve that peace and 
unity which accord with the exceeding love we bear 
each other." 

We further learn that Arcangela was subject 
to frequent fits of hypochondria, and that she was 
constantly ailing. Indeed, ill-health seemed to be 
more the rule than the exception at San Matteo. 
Maria Celeste herself was far from being always 
well ; sometimes she, sometimes another sister, 
sometimes half the convent was down with fever ; 
and rheumatism was frequently complained of. 

For the next ten years of Galileo's life and 
the rest of her own (1623-34), we shall be 
constantly in touch with this exquisite woman, 
in extracts from her letters, and the more we see 
of her the more we shall love her. 1 

On the election of Cardinal Barberini to the 
Papacy as Urban VIIL, Galileo conceived the idea 
of going to Rome to offer his congratulations in 
person, and to use his influence with the new 
Pope to obtain, at least, toleration for the Coperni- 
can doctrines, now no longer opposed by the 
weighty influence of Cardinal Bellarmine, who had 
died two years before. Remembering the warmth 
of Barberinis letters while Cardinal, Galileo had 
reason to hope from a Pontiff so enlightened at 

1 We can only give extracts from a few of these letters. The 
reader will find them more fully reported in Mrs Olney^s "Private 
Life of Galileo " ; while to those who can read them in the original 
we recommend Professor Favaro's u Galileo e Suor Maria Celeste," 
Florence, 1891, where all the letters are given in full. 


least this much ; while as regarded himself, he felt 
that he must have permission to teach the new 
astronomical doctrines, not merely as hypotheses 
but as actual truths, now or never ; and according 
as his desire was fulfilled or not, so would his 
life-work be complete or incomplete. 

Knowing her father to be an object of ani- 
mosity in so many quarters, the accession of 
Urban VIII. was a cause of great rejoicing to 
Maria Celeste, and having been favoured with a 
sight of the Pope's letters when Cardinal to 
Galileo, she wrote loth August 1623, when re- 
turning them, in a strain of eagerness : 

" I cannot describe the pleasure with which I 
perused the letters of the illustrious Cardinal, who 
is now our Pope, knowing as I do how greatly 
he loves and esteems you. I have read the letters 
several times, and now send them back as re- 
quested, having shown them to no one except 
Sister Arcangela, who is also much delighted to 
see how greatly you are favoured by such an 
exalted personage. May the Lord give you 
health to fulfil your desire of visiting his Holi- 
ness, so that you may enjoy a still greater measure 
of his favour. Seeing how many promises he 
makes in these letters, we hope that you will easily 
get something to help our brother. 1 I imagine that 
by this time you will have written a beautiful letter 
to his Holiness to congratulate him, and as I feel 

1 Vincenzio. Nothing is known of the youth of Galileo's son. In 
the first years after his arrival in Florence in 1612, he probably lodged 
with his uncle, Landucci, at least during his father's frequent absences. 
On 25th June 1619, he was legitimated by Grand-Ducal decree, and 
not long before the time of Maria Celeste's writing, he was sent to 
Pisa, under the care of Father Castelli, to study law. 


curious about it, I should like very much (if you do 
not object) to see a copy/' 

Poor simple soul ! She had not perceived the 
distance between her father, Philosopher and First 
Mathematician to a Grand Duke, and Maffeo Bar- 
berini, the Pope of Rome. Her father must have 
written at once to enlighten her on the degrees 
of comparison, for, in her reply of three days 
later, she confesses her ignorance with touching 
humility : 

" From your beloved letter I see how little 
knowledge of the world I must possess to have 
thought as I did that you would write immediately 
to such a personage to one who is, in fact, the 
head of Christendom. I therefore thank you 
for the hint you have given me, and feel sure 
that your love for me will induce you to excuse 
my ignorance as well as many other faults that I 
possess. I trust that always warned and reproved 
by you I may gain in knowledge and discretion. 

" Since we are not able to see you in con- 
sequence of your lingering indisposition, we must 
patiently resign ourselves to the Lord's will, Who 
permits all things for our good. 

" I put by carefully the letters you write me 
daily, and when not engaged with my duties I 
read them over and over again. This is the 
greatest pleasure I have ; and you may think how 
glad I am to read the letters you receive from 
persons who, besides being excellent in them- 
selves, have you in esteem/' 

A few days after, the convent steward, who 
had been sent with a message to the villa at 
Bellosguardo, brought back the alarming news 

1624] GALILEO ILL 199 

that Galileo was ill, and in Florence. Fearing 
that the illness might be more serious than usual, 
she packed off the steward again to the city to 
see him, and learn from himself the state of his 
health. She says in the affectionate little note 
of which the steward was bearer, that she never 
regrets being a nun, except when her dear father 
is ill, because then she would like to be with 
him. Galileo's illness seems to have been serious, 
for four days later (aist August) we find her 
writing again, and sending as an excuse a few 
biscuits baked in a mould representing a fish. 
The truth is, as she confesses in her note, she 
wants the steward to see her father, and learn 
his condition from his own lips, evidently placing 
little reliance on messages given by those around 
him. On 28th August she wrote again, expressing 
her grief at hearing that there was no improve- 
ment. She sent him a little present of four 
plums with the hope that, as they were not in 
as great perfection as she could wish, he would 
take the will for the deed. She then goes on to 
say : 

" Please remember that when you get an 
answer from those gentlemen in Rome, you have 
promised me a sight of it. I say nothing of the 
other letters you promised to send me, as I sup- 
pose they are at the villa at Bellosguardo." 

By the end of August, Galileo, though still far 
from well, was able to resume his correspondence, 
and on returning to his villa he sent her the letters 
she wished to see, also some thread and other 
trifles that she wanted. 


Feeiing his time and strength unequal to the 
literary demands upon them, he now seems to have 
begun to utilise his daughter's clear handwriting 
when he wished to have copies of particular letters 
or papers. Thus, in a note of this period, returning 
such a paper, she hopes that he will think the copy 
well done, as then, perhaps, he will let her copy 
some more, reminding him that to be occupied in 
his service is her great pleasure and contentment. 

With improving health, Galileo began to think 
it was time to prepare for his journey to Rome, and 
he wrote to some of his friends to sound them on 
the project To Prince Cesi he wrote, 9th October 

** I have in my head plans of no small impor- 
tance for the learned world, and perhaps can never 
hope for so wonderful a combination of circum- 
stances as the present to ensure their success, at 
least so far as I am able to conduce to it." 

Prince Cesi replied : 

" Under the auspices of this most excellent, 
learned, and benignant Pontiff", science must flourish. 
. . . Your arrival will be welcome to his Holiness. 
He asked me if you were coming, and when, and, 
in short, seems to love and esteem you more than 

Tommaso Rinuccini, to whom Galileo also 
wrote, replying 2Oth October, said : 

" I swear to you that nothing pleased his 
Holiness so much as the mention of your name. 
After I had been speaking of you for some time, 
I told him that you had an ardent desire to come 


and kiss his toe, if his Holiness would permit it, to 
which he replied that it would give him great 
pleasure if it were not inconvenient to you, and if 
the journey would not be injurious to your health, 
for great men like you, he said, must spare them- 
selves so that they may live as long as possible." 

Mgr. Ciampoli and other friends also wrote in 
the same confident strain. 

These replies, as gratifying as reassuring, 
Galileo appears to have sent to Maria Celeste for 
her perusal, as in her letters of October (1623) 
she refers to them. Amongst a great deal about 
Arcangela's illnesses, and repairs that she had 
been making to her father's linen, and her brother's 
collars she writes (2Oth October) : 

" I return the letters you sent me to read. 
They are so beautiful that my desire to see more 
of them is greatly increased." 

Again, on 2gth October, she writes : 

" I leave you to imagine how pleased I am to 
read the letters you constantly send me. Only to 
see how your love for me prompts you to let me 
know fully what favours you receive from these 
gentlemen is enough to fill me with joy. Never- 
theless, I feel it a little hard to hear that you intend 
leaving home so soon, because I shall have to do 
without you, and for a long time too, if I am not 
mistaken. Your lordship may believe that I am 
speaking the truth when I say that except you 
there is not a creature who gives me any comfort. 
But I will not grieve at your departure because 
of this, for that would be to complain when you 
had cause for rejoicing. Therefore, I too will 


rejoice, and continue to pray God to give you 
health to make a prosperous journey, so that you 
may return satisfied, and live long and happily. 
Although I know it is not necessary for me to 
do so, yet I recommend our poor brother to your 
kindness, and I entreat you to forgive him his 
fault in consideration of his youth, and which, 
seeing it is the first, merits pardon. I do beg and 
entreat you to take him to Rome with you, where 
opportunities will not be wanting to give him 
that assistance which paternal duty and your 
natural kindness will prompt you to seek out/' 

Vincenzio was then seventeen. What the 
escapade was which brought him into disgrace 
we are not told. And, unfortunately, this was 
not the only time that his sister had to intercede 
for him. In disposition this young man would seem 
to have resembled his uncle, Michelangelo. Years 
brought him no discretion. Wayward, selfish, idle, 
with a great capacity for spending money he had 
not earned, this only son was a constant thorn in 
his father's side. Castelli, who looked after him 
at Pisa with paternal solicitude, even to the buy- 
ing of his shoes and stockings, had to complain 
of his mulish obstinacy. A fault confessed was 
half atoned for, the good Father thought, and he 
strove hard to bring him to confession, assuring 
him that no punishment should follow. " But he 
is as hard as a stone, and one would think he was 
struck dumb by enchantment. As for me I am 
in utter despair about him." 

Maria Celeste had been busy working at her 
father's new set of dinner-napkins which had been 
cut too short, and must have pieces added ; and 

i62 4 ] FAMILY AFFAIRS 203 

not having heard from him for nearly a month, 
she was getting very anxious, On 2ist November 
she wrote : 

" I cannot rest any longer without news, both 
for the infinite love I bear you, and for fear lest 
this sudden cold, which generally disagrees so 
much with you, should have caused a return of 
your old pains and other complaints. I therefore 
send the man, who takes the letter purposely, 
to hear how you are and also when you expect 
to set out on your journey, ... As I have no 
bedroom of my own, Sister Diamante kindly 
allows me to share hers, depriving herself of the 
company of her own sister for my sake. But 
the room is so bitterly cold that, with my head 
in the state in which it is at present, I do not 
know how I shall remain, unless you can help 
me by lending me a set of those white bed-hangings 
which you will not want now. 

" Moreover, I beg you to be so kind as to send 
me that book of yours which has just been 
published [* II Saggiatore '], so that I may read 
it, for I have a great desire to see it. 

" These few cakes I send are some I made a 
few days ago, intending to give them to you when 
you came to bid us adieu. As now your departure 
is not so near as we feared, I send them lest they 
should get dry. 

" Sister Arcangela is still under medical treat- 
ment and is much tried by the remedies. I am 
not well myself, but being so accustomed to ill- 
health I do not think much of it. 

"P.S. You can send us any collars that want 
getting up." 




LONG delayed, first by illness and then by bad 
weather, whole tracts of country being under 
water, Galileo at length set out for Rome ist 
April 1624. Reaching Acquasparta on 5th April, 
he stayed a fortnight with his friend Prince Cesi, 
and arrived in Rome on the 23rd, provided with a 
warm letter of recommendation from the Grand 
Duchess Cristina to her son Cardinal de Medici. 
From Acquasparta he wrote to his daughter, 
telling her of the flattering reception he had met 
with from Prince Cesi, who was able to assure him 
that his presence in Rome was anxiously awaited 
" by great personages." On the other hand he was 
grieved to hear of the sudden death of Mgr. 
Cesarini, a warm friend whom he had both loved 
and honoured. This event, as Maria Celeste 
reminds her father (26th April), "gives food 
for reflection on the vanity and fallacy of all earthly 
hopes"; but she timidly adds, " I would not have 
you think that I write only to sermonise you, there- 
fore I will say no more." 

All the world of Rome was aware of the favour 

1624-1629] RESULT OF VISIT TO ROME 205 

in which the Pope held Galileo. His old friends, 
therefore, received him with greater delight than 
ever, and his enemies dared only to clench their 
fists behind his back. His letters express the great 
satisfaction which his reception afforded him ; but 
as regarded the object which was nearest his heart 
he was not so satisfied. Within six weeks he had 
had six long interviews with Urban VIII., had 
always been most affably received, and was allowed 
to bring forward all his arguments in support of 
the Copernican theory ; but all to no purpose ; the 
Pope listened to his arguments, but would not grant 
his earnest entreaties for, at least, a passive tolera- 
tion of the new doctrines. 

As soon as the Pope's attitude became known, 
Galileo's clerical friends had to be cautious, and 
avoided as far as possible all reference to the pro- 
hibited doctrines. One of these, Father Niccolo 
Riccardi, at once took his seat on the fence. 

" As to the truth or falsity of the theory/' wrote 
Galileo to Cesi on 8th June, "he accepts neither 
Ptolemy nor Copernicus, but quiets his soul in a very 
speedy manner. He sets angels to work at moving 
the heavenly bodies, and these make them go as they 
do go (however that may be) without the slightest 
difficulty or entanglement! Certainly this ought to 
be enough for us ! " 

Finding that his efforts to get the decree of 
5th March 1616 revoked were of no avail, Galileo 
resolved with a heavy heart to return home, after 
a six weeks' stay in Rome. On the eve of his 
departure, the Pope loaded him with favours which 
must have seemed to him like mockeries. His 


Holiness promised him a pension for his son, 1 and 
three days after sent a picture for himself; then 
two medals one of gold and one of silver, and 
quite a number of Agnus Dei ! Not content with 
these marks of favour, he addressed an official letter 
(Breve) to the Grand Duke, 8th June, in which, to 
the no small chagrin of Galileo's enemies, his 
Holiness not only did full justice to our philo- 
sopher's services to science, "the fame of which 
will shine on earth so long as Jupiter and his 
satellites shine in heaven," but laid special stress on 
his religious sentiments : 

" We have," he said, " observed in him not only 
literary distinction, but love of religion, and all 
good qualities worthy of the Papal favour. When 
he came to congratulate us on our accession we 
embraced him affectionately and listened with 
pleasure to his learned demonstrations, which add 
fresh renown to Florentine eloquence. We desire 
that he should not return to his native country 
without receiving from our generosity manifold 
proofs of our favour. And that you may fully 
understand to what extent he is dear to us, we 
give this honourable testimony to his virtue and 
piety. And, further, we assure you that we shall 
thank you for any kindness that you can show 
him ; and by imitating, or even surpassing, our 
fatherly liberality, you will add to our gratification/ 1 

Fruitless as was his journey to Rome as re- 

1 The pension of 60 crowns was granted on 2Oth March 1627, but 
owing to the religious exercises attached to it, Vincenzio would not 
accept it It was then transferred to a nephew, but as he proved un- 
worthy, it was finally settled on Galileo himself, on I2th February 1630, 
with an increase of 40 crowns, but with the condition that, as it was 
derived from ecclesiastical benefices, he should adopt the tonsure to 
which he is said to have consented. He drew the pension thus 
strangely obtained to the end of his life. 


garded the grand object of his life the emancipa- 
tion of the Copernican theory Galileo was yet able 
to do something for the advancement of science. 
He improved, if he did not invent, the microscope. 
The principle of the telescope and the micro- 
scope is to the mathematical optician one and the 
same. The former is merely made to collect 
parallel rays from distant objects; the latter, 
diverging rays from near objects. The invention 
of the one, therefore, could hardly fail to follow 
immediately upon the other ; and accordingly we 
learn that, very soon after inventing the telescope, 
Galileo adapted it for the examination of small 
objects. John Wedderburn, a Scotch student at 
Padua, in a defence of his master (published in 
1610) against the calumnies of Martin Horky (see 
p. 1 06 ante), states that he heard Galileo describe 
in what manner he perfectly distinguishes with 
his telescope the organs of motion and of the 
senses of the smaller animals, especially in a 
certain insect, which has each eye covered by a 
rather thick membrane, which, perforated with 
seven holes, like the visor of a warrior, allows it 

" Here hast thou," he continues, "a new proof 
that the glass concentrating its rays enlarges the 
object. In other animals of the same size, and 
even smaller, some of which have, nevertheless, 
brighter eyes, these appear only double, with their 
eyebrows and the other adjacent parts." 

In 1614, the Frenchman Tarde, Canon of the 
Cathedral of Sarlat (Dordogne), was travelling in 
Italy, and on arriving at Florence called on Galileo, 


whom he found ill in bed. Amongst other reports 
of this meeting Tarde says : 

''Galileo told me that the tube of a telescope 
for observing the stars is no more than 2 feet 
in length ; but to see well objects, which are very 
near, and which on account of their small size 
are hardly visible to the naked eye, the tube must 
have two or three lengths. He tells me that with 
this long tube he has seen flies which look as big 
as a lamb, are covered all over with hair, and 
have very pointed nails, by means of which they 
keep themselves up and walk on glass, although 
hanging feet upwards, by inserting the points of 
their nails in the pores of the glass." 1 

In "II Saggiatore n there is a further reference 
to a telescope arranged so that one can see very 
near objects very distinctly, even to the most 
minute particles ; and, finally, Viviani, in his " Vita 
dl Galileo," and in the laudatory inscriptions which 
he placed on the front of his house in Florence 2 
in 1693, records as a fact that Galileo presented 
a microscope to the King of Poland in 1612. 
All this goes to show that he was well acquainted 
with the uses of his invention qua microscope, 
and that he did not dwell upon them, or pursue 
them to greater length, is, no doubt, because his 
thoughts were wholly absorbed on its perfection 
as a telescope, and on the glorious field of astro- 
nomical discovery which it laid open to him. 
Certain it is, that for many years he gave the 

1 See Favaro's " Di Giovanni Tarde e di Una Sua Visita a Galileo " 
{Bulkttino di Bibliografia e di Storia delle Sdenze Matematiche e 
Fisickt) Rome, July 1887). A diagram of a microscope is reproduced 
from a contemporary MS. in the National Library, Florence. 

* Now No. 9 Vk San Antonino, formerly Via dell 7 Amore. 


matter little attention not until his visit to Rome 
of which we are now speaking, and when he 
found the microscope discussed as a novelty which 
nobody could understand. 

We have seen in our account of the invention 
of the telescope that Jansen, the optician of 
Middleburg, invented a form of microscope about 
1590, in which objects were seen inverted. One 
of these instruments he presented to the Archduke 
Charles Albert of Austria, who in turn gave it to 
Cornelius Drebbel, a Dutchman, then living in 
London. For many years after, the instrument 
was practically forgotten; but about 1621, Drebbel 
appears to have resumed its manufacture in 

In the following year Jacob Kuffler, a relative 
of Drebbel, brought a specimen to Rome, a present 
from M. de Peiresc of Paris to one of the Cardinals. 
From the letter which accompanied it, dated 7th 
June 1622, we take the following passage: 

"Your Lordship will receive the present letter 
from the hand of Signor G. Kuffler of Cologne. 
He will be able to show you an occhiale or telescope 
of a new invention (different from that of Galileo), 
with which he shows a flea as large as a cricket, 
and almost of the same shape, with its two arms 
and the other smaller legs, head, and almost all 
the body, covered with crusts or scales, like crickets 
or small shrimps. The little insects which generate 
in cheese become as large as flies, and are so dis- 
tinctly discerned that one sees them to have very 
long legs, a pointed head, and every part of the 
body quite distinct," 

Unfortunately, Kuffler died before he had time 


to explain the management of the instrument, and 
so it remained a mystery. Two years later, after 
many accidents and delays, two other specimens 
arrived, also sent by de Peiresc with brief in- 
structions as to their use. Apparently one was 
little more than a magnifying glass, which it was 
easy to understand ; but of the other and larger, 
consisting of two glasses, nobody in Rome could 
make anything, " although they had the help of 
mathematicians/ 1 

It was at this moment that Galileo arrived. 
The instrument was shown to him, and, as may 
be imagined, a very brief study told him not only 
how to use it but how to improve upon it. He 
at once told his friends that he had himself made 
a somewhat similar instrument many years pre- 
viously, " which magnifies things as much as 
50,000 times, so that one sees a fly as large 
as a hen." He quickly made some specimens, 
showing objects erect, which he sent to his 
friends, and soon his microscopes were in as 
great request as his telescopes. Amongst others, 
he sent one to Prince Cesi, on 23rd September 
1624, with the following interesting letter : 

" I send your Excellency a little spy-glass 
(occhialino) 1 for observing at close quarters the 
smallest objects, which I hope will afford you the 
same interest and pleasure that it does to myself. 
I delayed sending it because my first specimens 
were imperfect by reason of the difficulty in 

1 Galileo usually called the telescope occhicde or cannocchiale ; 
and now he calls the microscope occhialino. The name telescope was 
first suggested by Demisiani in 1612, and microscope by Giovanni 
Faber in pril 1625. 


fashioning the lenses. The object is placed on 
a movable circle (at the base of the instrument) 
which can be turned in such a way as to show 
successive portions, a single pose being unable 
to show more than a small part of the whole. 
As the distance between the lens and the object 
must be precisely adjusted in order to see things 
that are in relief, it is necessary to bring the glass 
nearer to or farther from the object, according to 
the parts to be examined. Therefore the little 
tube is made adjustable on its stand or guide. 
The instrument should be used in a strong light, 
or even in full sunlight, so as to illuminate the 
object as much as possible. 

" I have examined with the greatest delight 
a large number of animals, amongst which the 
bug is most horrible, the gnat and the moth very 
beautiful I have also been able to discover 
how the fly and other little animals are able to 
walk on window panes and ceilings feet upwards. 
But your Excellency will now have the opportunity 
of observing thousands of other details of the most 
curious kind, of which I shall be glad to have an 
account In short, one may contemplate endlessly 
the grandeur of Nature, how subtilely she works, 
and with what unspeakable diligence. 

" JP.S. The little tube is in two pieces, so that 
you may lengthen it or shorten it at pleasure." l 

Soon after his return to Florence, Galileo began 
to draw up a reply to an attack on the Copernican 
theory which had been addressed to him in 1616 
by Francesco Ingoli, then a lawyer at Ravenna, 
and afterwards secretary of the Propaganda in 
Rome. Coming at the time of his first encounter 

1 The only relic of these instruments now in existence is pre- 
served in the Tribuna di Galileo, Florence. The lenses are 


with the Inquisition, Galileo wisely refrained from 
answering it then. In 1618 an answer was pub- 
lished from the pen of that other Corypheus of 
science, Kepler, in his " Epitome of the Copernican 
Astronomy/' 1 but Ingoli did not consider himself 
beaten, and rejoined in a letter addressed to a 
high official of the Papal Court. Now, after the 
lapse of eight years, Galileo thought that, protected 
by the favour of Urban VII L, he might himself 
venture on a reply ; for although there was no 
hope of a public revocation of the decree of 5th 
March 1616, he thought, and his correspondents in 
Rome were of the same opinion, that the prohibi- 
tion would not be rigidly enforced against him. 

In this defence of the Copernican theory, he 
professes to be actuated by a double motive. On 
the one hand he wishes to show that, as he had 
given currency to it before it was condemned by 
ecclesiastical authority, he had not been the 
expounder of an improbable or unreasonable 
theory. On the other hand he wishes to prove 
to the Protestant Copernicans in Germany that 
the views of their great countryman had not 
been rejected in Catholic Italy from a disbelief 
of their probability, but " from reverence for 
Holy Scripture, as well as zeal for religion and 
our holy faith." After this strange introduction, 
and an assurance that he had no intention of 
representing the forbidden doctrine as true, he 
proceeds with vigour to refute all Ingoli's 

1 This work was placed on the Index Expurgatorius, loth ,March 
1619. Galileo had to smuggle a copy into Italy. 


In spite of his diplomatic preface, his friends 
in Rome, aware of the watchfulness of his 
enemies, advised him not to publish. Galileo 
wisely gave heed to their warnings, and so the 
work was only circulated in MS. copies. How- 
ever, several passages from it were brought under 
the notice of the Pope by Mgr. Ciampoli, and we 
learn from a letter of the latter to Galileo, 28th 
December 1625, that his Holiness highly approved 
them, 1 This to Galileo and his friends was a 
hopeful sign. Another was the failure of the 
agitation undertaken (as already mentioned) in 
the same year against "II Saggiatore." Father 
Grass! ventured, under pretext of a rejoinder to 
that work, to publish a fresh attack on its author 
full of spiteful personalities and " arguments'* of 
the most absurd kind Apparently Grassi, member 
though he was of the powerful Collegio Romano, 
could not find a publisher for this work (" Ratio 
Ponderum Librae ") in Rome, and had to bring it 
out in Paris in 1626, a circumstance which Galileo 
interpreted as another encouraging sign of the 
times. Again, in 1624 in a conversation on the 
subject with the Pope, the Cardinal Zollern 
(prompted by Galileo) represented that all the 
heretics of Europe considered the truth of the 
Copernican doctrine to be beyond doubt, and that, 
therefore, it would be necessary to be very circum- 
spect in coming to any resolution upon it, to which 
his Holiness replied that the Church had not con- 

1 In this work Galileo announced that he was preparing a treatise 
on the Flux and Reflux of the Tides, based on the hypothesis of the 
double movement of the earth. 


demned it ; nor was it to be condemned as heretical, 
but only as rash ; and he added, that there was no 
fear of any one undertaking to prove that it must 
necessarily be true. These and other indications 
tended to confirm Galileo in the opinion that, under 
the pontificate of Urban VI I L, the advocates of 
Copernicanism had little to fear, provided that 
the defence was so circumspectly handled as not 
to outrage the oft -mentioned decree of 5th 
March 1616. 

On this assumption (unfortunately a mistaken 
one, as we shall see) he now, 1626, resolved to 
carry out the great work which he had long 
projected, and which, from the vast and varied 
knowledge it displayed, and from its sparkling 
and incisive style, was to meet with greater 
success than had ever been attained by any 
scientific work. This was his " Dialogue on 
the Two Principal Systems of the World." 

During the next four years, 1626-29, Galileo 
was almost entirely engaged on the preparation 
of this great work. His official duties as 
Philosopher and First Mathematician to the 
Grand Duke did not take up much of his time, 
and his scientific correspondence was not con- 
siderable 1 ; but his work was sadly interrupted 
by frequently recurring illnesses, and as much so 
by family troubles of all sorts which sorely tried 
his patience. 

1 During this period he appears to have written one mathematical 
treatise bearing the curious title, " On the Estimation of the Value of 
a Horse." Here may also be noted, though the date is uncertain, his 
solution of a problem in chances (Sopra le scoperte de i dadi). This 
was many years before Pascal and Fermat wrote on the same subject 


From the paucity of his daughter's letters 
during 1625-26, it is certain he often went to see 
her at the convent. In one written in December 
1625 she sends her " dearest Lord and Father" 
two baked pears, a winter rose from the convent 
garden, and one of her (frequent) little sermons 
on the care of his health ; in another she sends 
Christmas greetings, and more collars and cuffs 
for "our Vincenzio." Sister Arcangela (who is 
often ill) is better, but still in bed. In a third 
little note she fears that Vincenzio is angry with 
her because she delayed sending the new collars 
he was in want of. Of this young man we learn 
that he was still pursuing his studies at Pisa, 
and spending more money than his father could 
afford, Galileo wrote to Castelli (2 7th December 

"For the future he is to be content with 
three crowns a month for pocket-money. With 
this he can buy plaster figures, pens, paper, or 
anything he likes, and he may consider himself 
lucky to have as many crowns as I, at his age, 
had groats." 

During the Carnival season of 1626, Galileo, 
relieved from attendance on the young Grand 
Duke, 1 remained closeted at Bellosguardo, ab- 
sorbed in his Dialogues. Maria Celeste had 
not seen or heard from him for some time ; the 
Carnival passed and Lent came, but no Galileo. 
Then she gave vent to her disappointment in 

1 Cosimo II., Galileo's old pupil and good friend, died in 1621. 
As his heir was then only ten years old, the government was carried 
on by Cosimo's mother jointly with his widow until 1627, when the 
son assumed power as Ferdinando II. 


words ; she is afraid that, in spite of all his past 
kindness, his love for his daughters must be on 
the wane, since he has left off coining. This 
apparently brought him to the convent, and 
with him came, as a peace-offering, a basket of 
eatables, rosemary, and citrons. After this, 
evidently, he was regular in his visits, for only 
two letters are extant belonging to this period. 

In the spring of 1627, Maria Celeste was 
herself really ill Self-denying and uncomplain- 
ing though she was, the coarse convent food 
was so unsuitable, that at length she asked for 
a little money to procure such comforts as were 
necessary to her recovery, The bread was bad, 
the wine sour, and the beef uneatable ; therefore, 
if there happens to be a tough old hen in the 
poultry-yard of the villa, she begs she may have 
it to make herself some broth. 

To the distractions caused by his own chronic 
ill-health, his daughters' frequent illnesses, and the 
not very satisfactory reports of his son's conduct 
at Pisa, were now to be added the worries of 
his invertebrate brother Michelangelo and his 
tribe of children. 

Since the death of their mother (loth August 
1620), the brothers communicated but little, if at 
all We have seen that Galileo had no reason 
to be pleased with his brother's behaviour in 
money matters ; and as long as Michelangelo 
could rub on without his brother's aid, he had no 
inducement to write. Now, however, it seems to 
have occurred to him that, after years of a 
great career, the friend of popes and princes 


must be full of riches as well as of honours ; 
the honours might be kept, but as regarded the 
riches, they ought to be divided amongst the 
noble family of the Galilei, of which he, Michel- 
angelo, was one, and as good as his brother, 
though (of course), through no fault of his own, 
he was less fortunate. If long ago his brother 
chose to cripple himself for years in order to 
pay Michelangelo's share as well as his own of 
their sisters' dowries, that was Galileo's own 
affair ; besides it was many years ago and could 
not now absolve him from the duty of paying a 
share of his brother's expenses in the bringing-up 
of a numerous family (only seven !). 

The letter proposing this arrangement is 
delicious. Writing to Galileo, 5th May 1627, he 
proposes sending his wife Anna Chiara to act as 
his brother's housekeeper. 

"This arrangement," he says, " would be 
good for both of us. Your house would be well 
and faithfully governed, and I should be partly 
relieved from an expense which I do not know 
how to meet, for Chiara would take some of the 
children with her, who would be an amusement 
for you and a comfort for her. I do not suppose 
that you would feel the expense of one or two 
mouths more. At any rate they will not cost 
you more than those you have about you now, 
who are not so near akin, and probably not so 
much in need of help." 

In reply Galileo offered to take his brother 
and his whole family and maintain them "till 
Michelangelo should succeed in procuring suitable 


employnient in Florence. Accordingly, in Sep- 
tember, they came to Bellosguardo, a party of 
eight the whole tribe, except the eldest daughter 
left behind with an aunt, who, It is to be hoped, 
duly appreciated the privilege of supporting her. 
Early in January 1628, Galileo sent the eldest 
boy, Vincenzio (nineteen years old) to Rome to 
study music, and Castelli, who was now settled 
there as Mathematician to the Pope, kindly took 
charge of him. 

Worn out with mental labour, sleeplessness, 
and the daily worries of a wild tribe of nephews 
and nieces, Galileo fell seriously ill again in 
February 1628, and thinking that the end was 
near he recalled his son from Pisa, and sent for 
his brother-in-law Landucci to be reconciled with 
him. 1 

On hearing of his convalescence, Michelangelo, 
who had returned to Munich only a few days 
before Galileo fell ill, wrote (5th April 1628), 
expressing his joy not so much for his brother's 
recovery, but "from what I know of our brother- 
in-law, I tremble to think what would have become 
of poor Chiara if you had died! " " I think now/' 
he goes on to say, "that with your good leave 
I shall have all my family back, for I do not wish 
them to be in danger of suffering unkind treatment 
one of these days. Meanwhile, I beg that you will 

1 Their relations were never cordial. Besides the old and long, 
standing quarrel over the payment of the dowry, Galileo had other 
grievances. Thus, in 1621 Landucci, thinking his merits not properly 
valued in Florence, quitted his country for a lengthened period and 
left his wife and family on Galileo's hands. See Favaro's " Galileo e 
Suor Maria Celeste," pp. 146 and 159. 


see to it that your servants pay Chiara proper 
respect and obedience, as I could on no account 
suffer her to be maltreated." 

The nephew, Vincenzio, had not been many 
months in Rome when Galileo began to receive re- 
ports of his misconduct Son of his father, vanity, 
idleness, and impertinence were the least of his fail- 
ings, and all Castelli's fatherly exhortations were lost 
upon him. The pension of 60 crowns which Urban 
VIII. had promised to settle on Galileo's own son 
was, on his refusal to fulfil the necessary conditions, 
to be transferred to this nephew, on the same terms, 
but, wrote Castelli : 

" He has little devotion ; my words enter at one 
ear and go out at the other. He wants to buy a 
diamond ring, and declares that he is neither monk 
nor nun, and will have none of my sermons. He is 
obstinate, impudent, and dissolute, and the insolence 
of his demeanour is such that I think he must be 
mad as well as vicious." 

While Castelli was writing in this strain, 
Michelangelo was asking .Galileo to pay his son's 
debts, and complaining that there was no one 
in all Rome capable of instructing him in the 

" Now the dear child will forget all the music he 
has learnt at Munich." 

" If you really mean," he continues in his letter 
of 8th June, "that there is no remedy to this 
disorder except my taking the children back again, 
I must do it, even if I go to Florence on foot 
What my troubles are nobody knows. You may 
say that you too have your own troubles ; I believe 


you, and I should think that seeing the ruin of 
these unhappy children should not be the least of 

He whines about his poverty and the expenses 
of a house, yet he would not economise by giving it 
up, because, forsooth, " the discomfort of lodgings 
would be unbearable." Wines In beer-drinking 
Munich were a luxury and dear, yet he must have 
good wine "for his health's sake." 

When at last Vincenzio had been sent away 
from Rome for his misdeeds, Michelangelo re- 
quested his brother to keep the young man till he 
came himself, as he intended to relieve him of the 
burden of maintaining his family. Galileo had 
meanwhile endeavoured to procure a page's place 
for a younger nephew, Alberto, in the Grand 
Duke's household, but the father objected that 
" dear Albertino's " tender age (he was born in 
1617) made it more proper that he should be 
served than that he should serve others. It would 
please him better if his Highness would confer a 
pension on the boy so that he may stay at home 
and learn to play on the lute ! As for Vincenzio, 
his conduct was incomprehensible to the father. 
" But/' he says, " I know he did not learn his 
wicked ways from me or any one else belonging to 
him. It must have been the fault of his wet- 

Michelangelo went to Florence in September 
1628, and took his family back to Munich, although 
he had not the wherewith to maintain them, and 
greatly against the wishes of his brother who was 
willing to keep them at Bellosguardo. This step 

i62 9 ] FAMILY AFFAIRS 221 

caused our long-suffering philosopher to lose all 
patience with a man who would only allow himself 
to be helped in his own way. They parted never 
to meet again, or even to correspond, for 
Michelangelo died on 3rd January 1631. 

From a letter of Maria Celeste, while these 
unpleasant matters were tormenting her father, we 
learn that she too was ill and miserable, jealous, 
perhaps, of the presence of aunt and cousins in her 
father's house. 

"I believe," she wrote 4th March 1628, "that 
it is possible for paternal love to diminish in con- 
sequence of children's ill-behaviour ; and this belief 
is confirmed by some signs which seem to tell me 
that your affection for us is not so cordial as it was. 
Besides which, though you are well now, you never, 
never write me a line. For more than a month I 
have suffered day and night from headache, and 
can get no relief. 

" I send a letter for Vincenzio, just to remind 
him of our existence which I think he must have 
forgotten, seeing that he never writes us a single 
line." 1 

This last illness of her father caused Maria 
Celeste the deepest anxiety. Unable to see for 
herself, she sent the convent steward on one 
pretext or another to himself see her father 
and bring her word. The man must have been 
devoted to this sweet Sister, else we think he 
would have objected to so many long walks to 
Bellosguardo, the bearer of such trifles as a 

1 He was at home from Pisa for the Easter vacation. As he had 
forgotten his sisters 7 existence we may be sure he was well supplied 
with collars. 


baked quince or a couple of pears, a winter rose, 
a preserved citron, or a phial of cinnamon water. 
In one of the affectionate little notes of this 
period (24th March 1628), she says: 

"Only in one respect does cloister life weigh 
heavily on me, namely, that it prevents my 
attending on you personally. My thoughts are 
always with you and I long to have news of 
you daily. As you were not able to see the 
steward the day before yesterday, I send him 
again to-day with these two pieces of preserved 
citron as an excuse." 

In June 1628, after six years' study of law at 
Pisa, Galileo's son, then twenty-two years old, 
took his Doctor's degree, from which, as we 
know, Galileo himself was debarred more than 
thirty years before, on account of the expense. 
His education finished, it was the father's wish 
that he should seek employment in some branch 
of the Civil Service of Tuscany, but Vincenzio 
preferred living an idle life at home, under 
pretence of aiding his father in his scientific 
and literary work. 

During the summer and autumn of 1628, 
Galileo's health was so indifferent as to put a 
stop to all exertion, and, consequently, to his visits 
to the convent distant over two miles across a hilly 
road. What little strength he had was reserved 
for his scientific correspondence and the composition 
of his Dialogues. But, although Maria Celeste 
knew this, she was anxious all the same. On loth 
December she wrote: 

"You may think from my long silence that 


I had forgotten you, just as I might imagine 
that you had forgotten the road to our abode, 
from the length of time that has elapsed since 
you came this way. However, as I know that 
the reason of my silence is that I have not an 
hour at present that I can call my own, so I 
think in your case that not forgetfulness but 
press of business keeps you from coming to see 
us. It is some comfort, meanwhile, to have 
Vincenzio's visits, as we thus get news of you 
on which we can rely." 

A daughter of Geri Bocchineri of Prato, 
Major-domo of the Grand Duke, was Maria 
Celestes best friend in the convent, and is 
frequently mentioned in her letters as Sister 
Luisa. Shortly after Vincenzio's return home 
from Pisa he paid his addresses to a sister of 
this lady, Sestilia Bocchineri, and was accepted. 
This news greatly delighted Maria Celeste, and, 
on 4th January 1629, she writes to know when 
and how she should congratulate the bride, and 
as regards a wedding present : " As I have not 
the means to do as my mind prompts, I must 
take advantage of your kind offer of help." 

Maria Celeste's satisfaction at the match was 
increased by her first interview with the bride. 1 
She thought she perceived in her such signs of 
affection for her father as augured well for the 
comfort of his declining years. Writing on 22nd 
March, she says : 

** Both my sister and I were much pleased 
with her affable manner and good looks. But 

1 The marriage took place at Prato on 29th January 1629, 
Galileo was present at the ceremony. 


what gave me the greatest joy was to see that 
she was fond of you, since from that we may 
judge that she will not be wanting in such 
loving attention as it would be our delight to 
render you were it permitted. . . . 

" If you could manage to send back the clock 
on Saturday evening, the Sister, whose duty it 
is to call us to matins, will be greatly obliged." 

From a later letter we learn that the clock, 
which had been sent first to one and then to 
another with no improvement, was going well 
now that Galileo had put it to rights. Some 
months later it got out of order again, and 
Vincenzio tried his hand at repairing it, but now 
(2 ist January 1630), it goes worse than ever. 
Yet, perhaps, its not going is more her fault 
than Vincenzio's, or, perhaps, it is because the 
cord is bad, or, perhaps she doesn't know, but 
anyhow she sends it to her father, for mended 
the clock must be, and that quickly too, else 
these nuns will let her have no peace. 

As evidence of Galileo's delightful faculty of 
turning his hand to everything, and of the odd jobs 
he was called on to do for the poor nuns of San 
Matteo, the following passage from Maria Celeste's 
letter of loth September 1630 is interesting : 

11 Now that the weather is getting cooler 
Sister Arcangela and I, with those of the nuns 
whom we love best, have planned to work 
together in my cell which is large; but the 
window is high, and wants 'glazing 1 in order 
that we may see a little better. I should like 
to send you the panels (or shutters) to glaze 
them with waxed linen, which even if old will 


do very well. But I wish to know first what 
you think not that I doubt your willingness, 
but because it is a piece of work fitter for a 
carpenter than for a philosopher." 

The common window of that period was no 
more than an opening in the wall fitted with a 
shutter in which was a hole (or holes) to let in 
light when the shutter was closed in very hot 
and very cold weathers. 

Towards the end of 1629, Galileo found himself 
face to face with yet another trouble which might 
have proved to be serious. He was menaced either 
with deprivation of his salary as Extraordinary 
Professor at Pisa, or with the loss of that leisure 
which had been the determining influence in his 
quitting Padua in 1610, and which he was now as 
anxious as ever to enjoy. Some ill-wishers at Pisa 
raised the question whether it was in the power of the 
Grand Duke to assign a salary out of the University 
funds to one who neither lectured nor resided there. 
This scruple had slept for nineteen years, so it is 
probable that those who now raised it reckoned on 
finding in young Ferdinando II. a less firm sup- 
porter of Galileo than his father Cosimo II. had 
been. But the matter did not proceed so far ; the 
theologians and jurists, to whom the question was 
referred, decided that the Grand Duke had the 
power, but to put the matter beyond all further 
dispute, his Highness appointed Galileo to an 
equivalent post in the magistracy of the University, 
so that he was left undisturbed in the stipend and 
leisure which were now more than ever necessary 
in his old age and shattered health. 






By the beginning of the year 1630, Galileo had 
completed his Dialogues, with the exception of an 
introduction or preface, an index, and a few finishing 
strokes here and there. In announcing this fact to 
his friends, he informed Prince Cesi that he intended 
going to Rome to see to the printing of the book a 
step of which the Prince highly approved. The 
state of affairs at Rome just then seemed very 
favourable for this enterprise. Galileo's devoted 
disciple Castelli had been called from Pisa in 1624 
to be mathematician to the Pope, and enjoyed great 
consideration with the Barberini family. This life- 
long friend also approved the design, and informed 
our philosopher (6th February) that Father Niccolo 
Riccardi, another old pupil and now chief censor of 
the press, had promised his assistance. 1 

Another letter of i6th March contained equally 
encouraging news. According to this, the celebrated 
Dominican monk, Tommaso Campanella, had just 
told the Pope that, a short time before, he had tried 

1 He was officially known as Master of the Sacred Palace. 



to convert some German nobles to the Catholic 
faith ; that they were favourably disposed until they 
heard of the prohibition of the Copernican theory, 
when they indignantly declined to have anything 
more to say to him. To this Urban replied ; " It 
never was our intention, and if it had depended 
upon us that decree would not have been passed." 
In other letters Ciampoli and Castelli urged their 
old master to set out at once for the Papal residence, 
" where they were longing for him more than for a 
lady-love." In the face of these fresh indications of 
an altered, or, at least, tolerant attitude towards 
science, we cannot be surprised at Galileo concluding 
that under Urban VI I L an infringement of the 
decree of 1616, in the spirit if not in the letter, such 
as his Dialogues undoubtedly were, would give no 
offence at the Vatican. 

While his friends were thus urging him to set 
out, his daughter, knowing how frail he was, con- 
templated the journey with anxiety. In her letter 
of 1 4th March, she hopes he will come to see them 
before he goes. Then, after saying how busy she 
is, and reminding him of his promise to send her 
what we now call " A Polite Letter- Writer/' comes 
the housewifely P.S. "If you want any collars 
washed please send them; and eat these fresh 
eggs for love of me." Maria Celeste is clearly the 
"scholared" one of the convent. She writes letters 
for the poor nuns ; helps the Mother Abbess in her 
official correspondence, and concocts petitions and 
begging letters to " people of quality, such as 
Governors, Workmen, 1 and such-like personages." 
i, may also mean administrators. 


For many days she goes on hoping to see her 
father, but he is absorbed in the final revision of 
his book, and has no time to go to San Matteo 
even to wish his daughters the customary Easter 
greetings. Maria Celeste could not refrain from 
an affectionate remonstrance ; she knows he is im- 
mersed in study, but she does not wish him to 
shorten his precious life for the sake of fame. He 
must take care of his health for his own sake, 
and for his children's sake. 

On 1 2th April, he found time to pay the long- 
wished-for visit, and he was made to promise 
another, which was to be a kind of family gather- 
ing in the convent parlour, where the two sisters 
would entertain their father, brother, and sister- 
in-law at a dinner (to be provided by Galileo). 
Wishing, dear soul, that the banquet should be 
worthy of the occasion, and fearing that her father 
in his scientific abstraction would send unsuitable 
things, she reminds him that she does not want 
either lemons or rosemary, but something more 
substantial, in particular a flask of his good wine, 
two cream cheeses, and some dish that will do 
to come after the roast. 

The Mother Abbess could not let pass such an 
opportunity of detailing the needs of the convent, 
and enlisting Galileo's good offices towards pro- 
curing some relief from Rome ; and she had as 
little hesitation in preferring the request as doubt 
of its being granted Why not? Maria Celeste 
was loved by her father who could refuse her 
nothing, Galileo himself was the Pope's friend, 
and surely he could obtain alms for her at Rome, 

i6 3 a] TAKES MS, TO ROME 229 

as easily as mend the convent clock ; lend her 
money when hard pressed ; and give them wine 
and fruits and other eatables from his cellar and 

Filled with hope and with his MS. complete, 
Galileo at length set out on ist May in a Court 
litter, and travelling fast arrived in Rome on the 
evening of the 3rd. Furnished with a letter of 
introduction from the Grand Duke J s chief secretary, 
Andrea Cioli, to the Tuscan ambassador, Francesco 
Niccolini, he was most hospitably received by that 
gentleman and lodged in the Embassy, where he 
quickly gained the friendship of the ambassador 
and his wife, which as we shall soon see was to 
be so useful to him. 

Soon after his arrival he had a long audience 
of the Pope, and wrote on i8th May to Florence 
in high spirits : " His Holiness has begun to treat 
my affairs in a way that permits me to hope for 
a favourable result/' Nevertheless, the result was 
anything but favourable; indeed, the toleration, 
to say nothing of the recognition, of the Copernican 
theory so ardently hoped for was as far off as 
even Urban VIII. would not object to the publi- 
cation, but certain conditions would have to be 
fulfilled. The title of the book, " Dialogues on the 
Flux and Reflux of the Tides/' was misleading 
and would have to be altered. The subject being 
really a discussion of the relative merits of the 
Copernican and Ptolemaic systems, this would 
have to be indicated in the title. The subject, 
moreover, would have to be treated from a purely 
hypothetical standpoint, and this fact must be 


clearly set forth in a preface or introduction. 
Then, the book must conclude with an argument 
which the Pope communicated to Galileo in 1624* 
and which his Holiness considered unanswerable. 
As great importance will attach itself to this argu- 
ment in the sequel, we beg our readers to note it 
carefully. It is as follows : God is all-powerful ; 
all things are therefore possible to Him ; ergo the 
tides cannot be adduced as a necessary proof of 
the double motion of the earth without limiting 
God's omnipotence which is absurd. 

Rather than forego the publication of a work 
towards which he had laboured and thought for 
over thirty years, Galileo consented to these con- 
ditions. Doubtless, he felt that such minds as 
were capable of following his reasoning in favour 
of Copernicanism would no more be prejudiced by 
the hypothetical warning in the introduction than 
by the unanswerable argument of the conclusion. 

Meanwhile, the MS. was submitted to Father 
Riccardi, the Papal censor, and by him passed 
on to his assistant Father Raffaele Visconti, who 
carefully went through it, altered many passages, 
and finally approved the work thus revised. By 
this time the middle of June had arrived, and 
Galileo was anxious to leave Rome before the 
great heat set in. Riccardi read over the MS. 
once more and then granted his permission for 
the printing of the work in Rome. Thus, by 
the end of June 1630, Galileo was back in Florence 

1 When Galileo's theory of the tides was being discussed in Rome. 
Doubtless, his Holiness brought forward his argument again at the 
recent interview. 


with his MS. duly revised and corrected, and 
with the ecclesiastical Imprimatur for its publica- 
tion in Rome, on the understanding that a 
preface and conclusion were added in accordance 
with the Papal wishes. But events were now 
at hand which long delayed Galileo's ardent 
desire to see his work speedily given to the 
world, and which involved complications after- 
wards taken advantage of by his watchful 

Soon after his return from Rome, Galileo wrote 
to his daughter, and from her reply of 2ist June, 
we learn that he was ill again : 

"Just as I was thinking of sending you a 
long lamentation because of your never coming 
near us, I received your most loving letter which 
shut my mouth completely. We were truly 
grieved to hear of your being ill ; but really, 
after making a journey at this time of the year, 
and with the plague everywhere, I do not see 
how it could be otherwise. I am astonished to 
hear of your going into Florence every day. 
Pray take a few days' rest ; do not even come to 
see us. We would prefer you kept well to the 
pleasure of your company/' 

The plague, already rife within the city walls, 
now began to spread to the suburbs. Even the 
fashionable Bellosguardo, whose reputation for 
salubrity equalled the beauty of its situation, was 
not spared. One of Galileo's own household, a 
glass-blower, was taken off early in October ; 
and soon after, his son Vincenzio, seized by a 
panic, fled with his wife to Prato, leaving his 
invalid father alone, and his seven-months'-old 


baby out at nurse in the neighbourhood of the 

On 1 8th October, Maria Celeste wrote : 

" I am troubled beyond measure at the thought 
of your distress, and am horrified at the sudden 
death of your poor glass-blower. I entreat you 
to omit no possible precaution against the present 
danger. I believe that you have by you all the 
remedies and preventives that are required, so- I 
will not repeat. Yet I would entreat you, with 
all reverence and confidence, to procure one more 
remedy the best of all, to wit, the grace of God, 
by means of true contrition and penitence. This 
is without doubt the most efficacious remedy both 
for soul and body. For, if in order to avoid this 
sickness it is necessary to be always of good 
cheer, what greater joy can we have in this world 
than the possession of a good and serene 
conscience ? . . . I pray your Lordship to accept 
these few words prompted by the deepest 

" I wish also to acquaint you with the frame 
of mind in which I find myself at present. I am 
desirous of passing away to the next life, for 
every day I see more clearly the vanity and misery 
of this present one. There I would hope that 
my prayers for your Lordship would have greater 

Ten days later, 28th October, she asks if her 
brother has really fled to Prato. 

"I was thinking, 1 ' she continues, "I would 
write to give him a piece of my mind, and advise 
him not to go, or, at any rate, not to leave the 
household so inconveniently situated. His going 
away in this manner really is exceedingly strange 


at this present juncture, as there is no saying 
what may happen. However, fearing to make 
matters worse, I did not put my intention into 
effect. I have the assurance that Almighty God 
will supply you by His providence where men 
fail you." 

From her next letters we infer that Vincenzio 
as still away, leaving his aged father with a 
scanty household. His idleness all along had 
been a cause of great pain to Galileo. With no 
energy to help himself, and too conceited to accept 
any appointment not commensurate with his ideas 
of his own importance, he preferred to live an 
ignoble life at his father's expense. On 2nd 
November, Maria Celeste tries to console her 
father in a long, prattling, and most touching 
letter. She entreats him sweetly not to brood 
over his loneliness, not to be too angry at 
Vincenzio's cowardly and ungrateful conduct, but 
to fix his thoughts on heaven : 

<f I pray you," she continues, "not to take 
the knife of these crosses and tribulations by the 
wrong end, but rather take it by the haft and use 
it to cut through all the imperfections which you 
may discover in yourself, that being thus freed 
from all impediments you may, as with a lynx- 
like eye by which you have penetrated the heavens, 
penetrate in like manner the things of this lower 
world, and so come to know the vanity and fallacy 
of all earthly things. ... I pray your Lordship 
pardon me if my chattering becomes wearisome. 
You incite me to it by telling me you are pleased 
to have my letters. I look upon you as my patron 
saint (to speak according to our custom here) to 


whom I tell all my joys and griefs, and finding 
you always ready to listen I ask, not indeed for 
everything I want, for that would be too much, 
but just for what I find most needful Now the 
cold weather is coming and I shall be quite 
benumbed if you do not send me a counterpane, 
for the one I am using at present is not mine, 
and the person to whom it belongs wants it 
back. The one you gave me, as well as the 
woollen one, I have given to Sister Arcangela. 
She prefers sleeping alone, and I am quite willing 
she should do so. But in consequence I have 
only a serge coverlet for myself. So I entreat 
my most beloved Devoto, who I know well cannot 
bear that I should want for anything. ... I send 
you two pots of electuary as a preservative against 
the plague. The one without a label consists of 
dried figs, walnuts, rue, and salt, mixed with honey. 
A piece of the size of a walnut is to be taken 
in the morning fasting, with a little good wine. 
They say its efficacy is truly wonderful. The 
contents of the other pot are to be taken in the 
same way. 

' ' You said in your letter that you had sent me 
the telescope, but you have forgotten to do so, 
therefore I remind you of it ; 1 also of the basket in 
which I sent you the quinces, as I want to send 
some more if I can meet with any." 

Galileo appears to have promised his daughters a 
visit in the beginning of December, but the tramon- 
tana (the cold wind from the Apennines) was 
blowing hard, and the old man dared not face it. 
In consequence, Maria Celeste sends one of her little 
notes (isth December) and some of the never- 

1 She uses the word occkiale^ but Professor Favaro thinks she 
meant occhialino or microscope, which no doubt Galileo intended for 
her amusement. 


failing preserved citron. She also asks for the 
wherewithal to make a few Christmas presents ; 
some stuff to make a door-curtain ; and a few trifles, 
such as reels, sulphur matches, wicks, and tags. If 
not in the house he was not to send out for them, 
she would prefer to go without them, to running the 
risk of the messenger bringing back the plague from 
the city. 

In a letter of i8th February 1631, Maria Celeste 
says : " I am quite confused at hearing that you 
keep all my letters. I fear that your great love for 
me makes you think them more perfect than they 
are." This little fact shows very clearly the esteem 
in which he held her. He had, no doubt, been pour- 
ing out his tortured soul to her. Stung by his son's 
misconduct, by his brother's selfish waywardness, 
and by the little consideration of other relatives, it 
must have been a comfort to him to turn to the 
only one of his family whose life was a mingled 
hymn of gratitude for his kindness and of prayers 
for his welfare. It must have helped to soothe his 
aching heart to know that there was one being in 
the world who would not misunderstand his motives 
and actions, and whose sympathies were his in joy 
and in sadness. 

Early in the summer of 1631, feeling age and 
infirmity creeping surely over him, he began to 
think of a change of residence from Bellosguardo to 
the neighbourhood of the convent, where he would 
be able to enjoy more often his daughter's society. 
Maria Celeste's letters show how eager she was to 
hear of a house which would combine vicinity to the 
convent with a good situation, and a rent suitable to 


her father's much-drained purse. House-hunting 
in the neighbourhood of Florence was not then the 
easy work it is nowadays, such villas as existed 
being mostly occupied by their owners. Vincenzio, 
who appears to have got over his sulks and fear of 
the plague, was back again with his father, and 
helped in search for a house. Maria Celeste heard 
of two or three, but there was something against 
them all, and it was not until August that she 
heard of one which she considered suitable in every 
way. Writing on the I2th, she says : 

" I am so anxious to have you in the neighbour- 
hood that I am constantly enquiring if there is any 
place near here to let. I have just heard of a villa be- 
longing to Signor Esau Martellini which is situated 
on the Piano de Giullari, and bounds our garden. 
I write at once to tell you that you may see if it be 
to your liking. I should be glad indeed if it were, 
as then I should not be obliged to remain so long 
without news of you as is the case at present" 

Shortly afterwards, Dame Piera (Galileo's old 
housekeeper) going to the convent with a basket of 
provisions, rejoiced the daughter's heart by telling 
her that there was every prospect of the villa Mar- 
tellini being taken. As Maria Celeste's last letter 
addressed to Bellosguardo is dated 3oth August, it 
would seem that very soon after, Galileo took up his 
abode in the village of Arcetri in Martellini's villa, 
then called " II Giojello" (the jewel), and now known 
as Villa Galileo. There, not five minutes' walk 
from the convent (indeed the grounds of the two 
houses adjoined) he was able to have daily inter- 
course with his daughters, and Maria Celeste no 


longer found difficulty in procuring a messenger if 
necessary to send affectionate enquiries about his 
health, or little presents from the still-room and 

" Nearer we hail 

Thy sunny slope, Arcetri, sung of old 
For its green wine ; dearer to me to most, 
As dwelt on by that great astronomer, 
Seven years a prisoner at the city-gate, 
Let in but in his grave clothes. Sacred be 
His villa (justly was it -called the Gem ! ) 
Sacred the lawn, where many a cypress threw 
Its length of shadow, while he watched the stars ! 
Sacred the vineyard, where, while yet his sight 
Glimmered, at blush of morn he dressed his vines, 
Chanting aloud in gaiety of heart 
Some verse of Ariosto ! " 

ROGERS' Italy. 

Arcetri is full of memories of the great Florentine 
philosopher. On the road front of his villa is a 
white marble slab with a long inscription placed 
there in November 1788, by Gio. Battista Nelli, 1 
and commemorating the fact that Galileo lived 
there from the Kalends of November 1631 to the 
Ides of January 1642. Over the inscription is a 
bust with the words : " This effigy of the divine 
Galileo was erected in 1843 by Anton: Filippo 
Marchioni." 2 

On the way back to town, soon after leaving 
Arcetri, one comes to the picturesque old Torre del 
Gallo, from the tower of which one gets a glorious 

1 One of his biographers "Vita e Commercio Letterario di 
Galileo Galilei," Lausanne, 1793. For inscription, see Alberi's 
edition, vol. xv. p. 395. 

* On the front of a house opposite to the entrance to the villa is an 
old sun-dial said to be the work of Galileo, 


view of the surrounding country, extending from 
the wooded heights of Vallombrosa on the east, to 
the distant Carrara mountains on the west; and 
from Certosa and away along the Roman road to 
the south, to the heights of old Fiesole on the north, 
with the Val d'Arno and Florence in between. 

" Of all the fairest cities of the earth 
None is so fair as Florence." 

-ROGERS' Italy. 

A chamber in the tower is arranged as a 
Galilean Museum, and is full of relics of the 
philosopher and his contemporaries, as portraits, 
busts, engravings, autographs, and medals ; instru- 
ments of various kinds, as telescopes, thermometers, 
hour-glass, etc. Amongst the paintings we would 
particularly direct the visitor's attention to those of 
Galileo before the Inquisition ; Galileo, blind and 
in bed, dictating to his son and his last disciples 
Viviani and Torricelli ; and portraits of the two 
latter. 1 

It is popularly supposed that Galileo used 
the Torre del Gallo as an observatory. There 
seems, however, to be no ground for this belief; 
but that he sometimes came here to enjoy the 
grand panorama displayed from the top is likely 

Not far from the Torre del Gallo, and still on 
the way to Florence, one comes to the Piazza degli 
UganellL Here the great painter Sustermans 

1 Quite recently the Torre del Galio has changed hands, and the 
Galilean relics, etc., have been dispersed. 

The Torre del Gallo, Arcetri, Florence. 

{To face /. 238. 


lived, and here in 1635 he painted his celebrated 
portrait of Galileo. A photographic copy of this 
is reproduced as the frontispiece to this volume. 
This picture, which is thought by experts to be 
Sustermans' chef cfceuvre, has a history. It was 
sent by Galileo as a present to his friend and .cor- 
respondent, Elia Diodati of Paris. Twenty years 
later, and as a special favour, it was returned to the 
Grand Duke; and later still it was placed in the 
Uffizi Collection by Cardinal Leopoldo de Medici 
" In order to show to all two marvels of nature, in 
the person of him who is represented, and in the art 
of the painter/* 1 

All this time, from soon after his return from 
Rome, Galileo was tormented with the obstacles 
and delays which he encountered in the printing of 
his Dialogues. It would detain us too long and be 
little profitable to set out these complications in 
detail ; but they are so well summarised by Galileo 
himself in a letter of /th March 1631, to Chief 
Secretary Cioli, that we venture to reproduce it as 
follows : 

" As your Lordship knows, I went to Rome for 
the purpose of getting permission to publish my 
Dialogues, and to this end I put them in the hands 
of the Master of the Sacred Palace, who committed 
them to the care of his colleague, Father Raffaele 

1 Sustermans was born in Antwerp 1597, settled in Florence 
and there died in 1681. There is another portrait of Galileo in the 
Pitti Palace Collection (No. 106, Hall of Mars), which has been 
attributed to Sustermans, but is now supposed to be the work of one 
of his pupils. See on this disputed point Favaro's "Document! 
Inediti per la Storia dei Manoscritti Galileiani," Rome, 1886, pp. 102-3 
and 109. 


Visconti, that he may examine them with the 
greatest attention, and note any doubtful matter or 
any conceit of imagination requiring correction, 
which (at my own request also) he did most 
thoroughly. And when I entreated the Rev. 
Master to grant me the required licence, his 
Reverence signified his wish to read the whole 
MS. through once more. This was done, after 
which he returned the book with the licence signed 
with his own hand; whereupon I, having been in 
Rome for two months, returned to Florence, in- 
tending to send back the book (as soon as I had 
added the dedication or preface, the conclusion, and 
a few other necessary things) to the illustrious 
Prince Cesi, President of the Lyncean Academy, 
who had always superintended the printing of my 
works. But owing to the death of this Prince 
[on 2nd August 1630] and the interruption of 
communications [by the plague], I was hindered 
from printing the work in Rome, and decided on 
having it done here. I had arranged matters with 
an able printer and publisher, and had procured the 
licence of the Rev. Vicar, and of the Inquisitor, and 
also of the illustrious Signor Niccolo Antella. I 
informed the Rev. Master of the Palace of all that 
had taken place, and of the impediments in the way 
of the printing in Rome. Whereupon he informed 
me, through our Ambassador, that he wished to 
have another look at the book, and that I was to 
send him a copy. On this I came to you, as you 
know, to ask if it were possible to send such a large 
volume to Rome with security, and you replied 
certainly not, and that letters were hardly safe. 
On this I wrote again, stating the impediments, and 
offering to send the preface and the end of the 
book, to which the superior authorities might add if 
they saw fit, or take away, or add notes of explana- 
tion ; for I myself do not refuse to call these 


thoughts of mine chimeras, dreams, paralogisms, 
and vain imaginations, submitting the whole to the 
absolute wisdom of my superiors. As to the further 
revision of the body of the work, I suggested it 
might be done here by some person named by the 
Rev. Father. He was content that it should be 
so, and accordingly I sent him the preface and the 
end, and he authorised Father Jacinto Stefani, 
Counsellor of the Inquisition in Florence, to revise 
the work. This he did with the greatest care, 
observing even the minutest points which neither 
to him nor to my most malignant adversary could 

five the slightest umbrage. 1 Indeed, the Rev. 
ather declared that the reading of my book 
had drawn tears from him more than once, when 
he saw with what humility and reverent submission 
I deferred to the authority of my superiors. And 
he declares, as do all who have read the book, that 
I ought to be entreated to publish it, instead of 
being hindered in so many ways, of which I need not 
here adduce examples. 

" Weeks and months ago I heard from Father 
Castelli that he had often met the Rev. Master 
who had given him to understand that he was 
going to send back the preface and the end, 
arranged to his entire satisfaction ; but this has not 
yet been done. 2 The papers have been thrown 
aside into some corner, and my life is wasting away, 
and I am in continual trouble. I went into town 

1 " The reviser here, finding nothing to alter, but in order to show 
that he had gone carefully through the MS., contented himself with 
substituting some words for others, as for instance, in several places, 
'universe 1 for ' nature, 1 { quality' for Attribute,' 'sublime spirit' for 
* divine spirit excusing himself to me by saying he foresaw that I 
should have to do with fierce foes and bitter persecutors, as indeed 
has come to pass." Galileo to Elia Diodati, I5th January 1633. 

2 Evidently some intrigue was afoot in Rome to stifle the book. 
Castelli wrote 24th August 1630, recommending for many most 
weighty reasons, which he did not wish just then to put on paper, 
that the work be printed in Florence, and as quickly as possible. 



yesterday at my Serene Master's command, to see 
the designs for the facade of the Cathedral, and also 
wishing to avail myself of his kindness, so that, 
taking counsel with your Excellency, some means 
may be found for making the Rev. Master explain 
himself as that the Ambassador be instructed to 
signify his HIghness's desire for a termination of 
this weary business, and to let him know what sort 
of man his Highness has for a servant. But so ex- 
ceedingly troubled was I that I could neither speak to 
his Highness nor look at the designs. Just now a 
messenger from Court has come to know how I 
am, and truly I am in such a state that I should 
not have risen from my bed had I not wished so 
particularly to tell your Lordship of this business, 
and to beg you to do for me that which I was 
unable to do yesterday, and to take the matter into 
your own hands, so that I may, while life yet 
remains, see what result I may expect from all my 
long and heavy labours. I send this by the hand 
of the Court messenger, and shall await your reply 
through Signor Geri Bocchineri. And since his 
Highness is so anxious to learn the state of my 
health I beg you to tell him that I should be pretty 
well in body, were I not so afflicted in mind." 1 

The ambassador, Niccolini, was instructed to 
act in accordance with Galileo's wishes, and after 

1 In this letter Galileo refers incidentally to one of the few occa- 
sions on which his advice was sought in the public service, so far as 
we know from documentary evidence. Another occasion occurred a 
short tim'e previously, namely, a disastrous inundation of the river 
Bisenzio. His report, in which he recommended the canalisation of 
the river, is dated i6th January 1631, and addressed to Raflaello 
Staccoli, the Auditor-General of Tuscany. On the 22nd July of the 
same year, he addressed another report to the Grand Duke on the 
proposed canalisation of the Arno. For some interesting information 
on these subjects, see Napier's "Florentine History," London, 1847, 
vol. vi pp. 393-448. 


more months of vexatious objections and delays, 
and not until, as Niccolini says, "formally pulled 
by the hair," Riccardi sent back the preface 
and end, now quite In order, to the censor in 
Florence. In his covering letter of lyth July 
1631, he says : 

" Conformably to the orders of our Lord (the 
Pope) respecting Signor Galileo's book, besides 
what I wrote to your Reverence concerning the 
body of the work, I send you the preface, with 
liberty to the author to alter or embellish as to 
the wording, so as the substance is preserved. 
The end may be treated in the same way." 

By early autumn, and after a second Revision 
of the whole work by Father Stefani in accordance 
with precise instructions from Rome, all the con- 
ditions of the censorship were finally complied 
with, and permission to print the book in Florence 
was issued in due form of Imprimatur. In all 
these annoying hindrances Galileo had a foretaste 
of the persecution which was to be his lot for the 
rest of his life. 

We shall devote the rest of this chapter 
to giving an idea of the plan and style of the 
work, and a rdsumt of its contents. The book, 
which is dedicated to Ferdinando II., bears the 
following title, unusually long in an age of long 
titles : " Dialogue of Galileo Galilei, Lyncean, 
Mathematician Extraordinary of the University 
of Pisa, Philosopher and First Mathematician 
of the Most Serene Grand Duke of Tuscany ; 
where in meetings of four days are discussed 
the Two Principal Systems of the World, in- 


determmately proposing the Philosophical and 
Natural arguments, as well on one side as on 
the other." It is written in Italian, and in a 
style adapted not for the learned alone, but 
intelligible and attractive to every one of ordinary 
education. His reason for writing in Italian 
instead of in Latin the usual vehicle fo 
philosophical subjects is characteristic. 

"I write in Italian," he says, " because I wish 
every one to be able to read what I say. I see 
young men brought together indiscriminately to 
study to become physicians, philosophers, etc., 
who although furnished, as Ruzzante might say, 1 
with a decent set of brains, yet being unable to 
understand things written in gibberish, assume 
that in these crabbed folios there must be some 
grand hocus pocus of logic and philosophy much 
too high up for them to jump at. I want such 
people to know that as Nature has given eyes to 
them just as well as to philosophers for the purpose 
of seeing her works, so she has given them brains 
for examining and understanding them." 

The dialogue is carried on by three inter- 
locutors, two of whom adduce the scientific 
reasons for the double motion of the earth, 
while the third honestly tries to defend the 
opinions of the Ptolemaic and Aristotelian 
schools. Galileo gave to the defenders of the 
Copernican doctrine the names of two of his 
warmest friends, both long dead Filippo Salviati 
of Florence (died 1614), and Gio Francesco 

1 Ruzzante, whose real name was Angelo Beolco, was a Paduan 
(1502-1542), and the writer of racy stories and ridiculous incidents in 
the Paduan dialect 

j6 32 ] PLAN OF THE WORK 245 

Sagredo of Venice (died 1620). Salviati is the 
special advocate of the Copernican doctrines ; 
Sagredo is witty, impartial, and open to con- 
viction, a half convert, but an acute and ingenious 
one. To him are allotted the objections which 
seem to have some real force, as well as lively 
illustrations and digressions which would be 
inconsistent with the gravity of Salviati's 
character. Simplicio, a name borrowed from 
the noted Sicilian commentator of Aristotle who 
wrote in the sixth century, 1 is of course a con- 
firmed Ptolemaist and Aristotelian, and produces 
successively all the scientific arguments of the 
peripatetic school ; and as these fail to convince, 
he has recourse to all the arts of sophistry. 
Placed between the wit and the philosopher, 
it may be guessed that his case fares badly, in 
fact, he is chaffed and confuted at every turn, 
so that no unbiassed reader can fail to perceive 
the superiority of the modern theory; and as 
Galileo puts into the mouth of Simplicio not 
only every possible argument in favour of his 
case, but also every possible objection to the 
other side, this superiority is made to appear 
all the more striking. 2 

The condition that the Copernican doctrine is 
only to be treated as an hypothesis is ostensibly 

1 Miss Clerke (verbo Galileo, " Encyc. Brit") says that this choice of 
name was " doubtless instigated by a sarcastic regard to the double 
meaning of the word"; but there seem to be no grounds for the 
suggestion. Indeed, Galileo says distinctly in his preface that the 
name was suggested by that of Aristotle's commentator. The name is 
used again in his " Dialogues on the New Sciences," published in 1638. 

2 A favourite method, see p. 161 ante. 


coxnpiied with, If Salviati or Sagredo show the 
untenableaess of some Ptolemaic axiom, or add 
a stone to the Copernican structure, a remark 
is interpolated by one or other to weaken the 
effect. When, for instance, it is said that the 
final decision in the controversy rests neither 
with mathematics and physics, nor with logic 
and philosophy, but with "a higher insight"; 
or when Salviati repeatedly asserts that he does 
not wish to maintain the Copernican doctrines as 
true, and uses the qualifying word " possible," 
or speaks of them as " fantasies" and "most 
vain chimeras/' the reader cannot fail to see 
that these reservations, which always occur 
at critical moments, are made with the purpose 
of appeasing the censors. 

When we remember its history we cannot be 
surprised that the preface or introduction has no 
logical agreement with the contents of the 
Dialogue. It is addressed "To the Discreet 
Reader," and runs as follows : 

"Some years ago a salutary edict was 
promulgated at Rome, which, in order to obviate 
the perilous scandals of the present age, enjoined 
an opportune silence on the Pythagorean opinion 
of the earth's motion. Some were not wanting 
who rashly asserted that this decree originated, 
not in a judicious examination, but in ill- 
informed passion ; and complaints were heard that 
counsellors totally inexperienced in astronomical 
observations ought not by hasty prohibitions to 
clip the wings of speculative minds. My zeal 
could not keep silence when I heard these rash 
lamentations, and I thought it proper, as being 

i6 3 2] FLAN OF THE WORK 247 

fully informed with regard to that most prudent 
edict, to appear publicly as a witness of the actual 
truth. I happened at that time to be in Rome ; 
I was admitted to the audiences, and enjoyed the 
approbation of the most eminent prelates of that 
Court; nor did the publication of the aforesaid 
decree occur without my receiving some prior 
intimation of it Wherefore it is my intention 
in this present work to show to foreign nations 
that L- much of this matter is known in Italy 
(and particularly in Rome) as ultramontane 
diligence can ever have formed any notion of, 
and (collecting together all my own speculations 
on the Copernican system) to show them that 
the knowledge of all these preceded the Roman 
censures, and that from this country proceed not 
only dogmas for the salvation of the soul, but 
also ingenious discoveries for the gratification of 
the understanding. With this object I have 
taken up in the dialogue the Copernican side of 
the question, treating it as a pure mathematical 
hypothesis, and endeavouring in every artificial 
manner to represent it as having the advantage, 
not over the opinion of the stability of the earth 
absolutely, but over it as taught and defended 
by some who profess to be peripatetics, but 
retain only the name, and are content, without 
improvement, to worship shadows, not philoso- 
phising with their own reason, but only from 
the recollection of four principles imperfectly 
understood." 1 

The conclusion agrees no better than the 
preface with the body of the work. At the end 
of the fourth day, which is almost wholly taken 
up with the question of the tides, comes naturally 

1 It will be noted that this preface is in much the same style as 
the introduction to his Ingoli letter. See p. 2*2 ante. 


the Popes 4 < unanswerable " argument of 1624 
(p. 230 ante). Salviati treats it accordingly : 

"It is," he says, "an admirable and truly 
angelic argument, and perfectly in accord with that 
which, coming from God Himself, permits us to 
discuss the constitution of the world doubtless 
with the view of preventing (by exercising them) 
the diminution and enfeeblement of our intellectual 
faculties, while withholding from us the power of 
fully comprehending the works of His hands. May 
this exercise (permitted and ordained by God) en- 
able us to see and admire His greatness, which is 
all the more necessary since we shall never be able 
to penetrate the depths of His infinite wisdom. " 

Sagredo then says : 

" Let this reflection be a fitting conclusion to 
our four days' discussion. And now, if Salviati 
desires some repose, our curiosity will concede the 
delay, but only on condition that at his earliest 
convenience he will satisfy us as to the problems 
reserved for future meetings. For myself, I am 
extremely anxious to hear his exposition of the 
elements of the new* science of local motions, 
natural and violent, as elaborated by him." 

As regards the contents of the Dialogues, we 
can only give an outline. Salviati opens the 
conference by defining its object, which is to 
examine all the physical arguments evoked for 
and against their opinions by the defenders of 
Aristotle and Ptolemy on the one hand, and of 
the Copernican doctrine on the other. 

No discussion could be undertaken without first 
enquiring into Aristotelian doctrines, which formed 
the basis of current theory. In a few words those 

i6 3 a] FIRST "DAY" 249 

amounted to a statement, that whereas things 
earthly are imperfect and full of change, things 
heavenly are eternal, unchangeable, and perfect. 
Salviati proves that this statement, in the spirit in 
which it was usual to accept it, was in reality un- 
tenable. The telescope showed him imperfections 
on the sun's surface, which was contrary to the be- 
lief that that body was unchangeable and free from 
blemish. He lays no great stress on the instance 
of comets (whose real nature Galileo never under- 
stood), but quotes the recent new stars (of 1572 
and 1604) as instances of further change in the 
heavens. He thus prepares the way for a still 
wider departure from Aristotelian theory ; he insists 
that the time has come to consider the nature of 
the world de novo, respectfully suggesting that 
Aristotle, had he the opportunities which the in- 
vention of the telescope afforded, would himself 
have been the first to realise the inadequacy of 
his dogmas on this subject. 

Salviati proceeds to poiit out certain resem- 
blances between the earth and moon and the 
more distant heavenly bodies. It is shown that 
the moon only shines in virtue of the sunshine 
falling on her. The idea that the earth might 
similarly appear luminous to any inhabitant could 
one be imagined to exist on the moon is less 
familiar, and less readily accepted. And yet the 
visibility of the moon during a total eclipse of 
the sun, and the appearance " of the old moon in 
the arms of the new" (as we now speak of it), 
are more probably due to reflected earth-light than 
to any other cause. This is discussed at some 


length, and the phenomena of Venus's phases 
(revealed by the telescope) are shown to be 
similar to those of the moon, and may be ex- 
plained as due to the same cause. Venus then, 
like the moon, owes her brilliance to sunlight 
falling on her. The same probably applies to 
Mercury and Mars. The obvious inference seems 
to be that all of these heavenly bodies are not 
so unlike the earth as men had always been 
taught to believe. Points of resemblance there 
certainly are, and there may be many more, which 
the distance of the planets alone prevents us 
from discovering. Salviati refers to the common 
spherical form of earth, sun, moon, and planets, 
suggesting the existence of a common cause for 
that shape. The passage is striking enough to 
quote : 

" Just as from the mutual and universal tendency 
of the parts of the earth to form a whole, it 
follows that they all meet together with equal in- 
clination, and, that they may unite as closely as 
possible, they assume the spherical form, and so 
we ought to believe that the moon, the sun, 
and other mundane bodies are also of a round 
figure, if for no other reason than from a common 
instinct and natural concourse of their component 
parts ; whence, if by accident any one should be 
violently separated from its whole, it is reasonable 
to believe that spontaneously and of its natural 
instinct it would return*" 1 

\ Here follow some remarks which show that the idea of universal 
gravitation hovered round Galileo's mind without fully entering it. 
He perceived the analogy between the power which holds the moon 
in the neighbourhood of the earth, and compels Jupiter's satellites to 
circulate round their primary, and that attractive power which the 
earth exercises on bodies at its surface ; but he failed to conceive the 

1632] SECOND "DAY" 251 

Having laid stress on the resemblance of earth 
and planets as a probable theory, SalviatI proposes 
for them all a similar motion round the sun one 
of the two main points of the new Copernican 
doctrines. He shows how by this hypothesis the 
apparent paths of the planets can all be explained. 
And the simplicity of his explanation as contrasted 
with the Ptolemaic system appeals to common- 
sense, in a way which in itself almost carries 
conviction. A glance through a telescope turned 
towards Jupiter shows a family of small bodies 
circling round a great planet; here one could see 
on a small scale the very thing that Copernicus 
had described as going on in the case of planets 
and sun on a much larger scale, the sun being 
in the latter case the central body which corre- 
sponded with Jupiter in the other, 

On the second "Day" the discussion passes 
on to the other chief point in the Copernican 
hypothesis, that the daily motion of the stars is 
only apparent, being due to a real daily rotation 
of the earth on its polar axis. Various objections 
are brought against this. The opponents of the 
earth's diurnal motion maintained that, if that 
motion were real, a stone dropped from the top 
of a tower would not fall at its foot. In the same 
way it was stated that a stone dropped from 
the masthead of a ship would fall near the stern, 
in consequence of the ship's velocity. But, strange 
as it seemed to Simplicio, it is nevertheless true 

combination of central force with initial velocity, and was disposed to 
connect the revolutions of the planets with the axial rotation of the 
sun a notion which tended more towards Descartes' theory of vortices 
than towards Newton's theory of gravitation. 


that the stone falls at the foot of the mast, the 
ship's motion, provided it be uniform, having no 
power to disturb its fall In a variety of forms 
the argument is brought forward, that if the earth 
be really rotating we on its surface ought to be 
sensible of the fact, either by our direct power of 
feeling, or else by irregularities in the motion of 
the things about us. There is a single reply to 
all such contentions, viz., all bodies on or near 
the earth's surface share the earth's motion, even 
the lower parts of the atmosphere being carried 
on by it, and, therefore, as all such things have a 
common motion, their relations to one another 
are just as if the motion did not exist. " Motion is 
so far motion (and as motion it operateth) by how 
far it hath relation to things which want motion ; 
but in those things which all equally partake 
thereof it hath nothing to do, and is as if it 
never were." Salviati justifies this contention by 
a forcible illustration. A ship is out for many 
months on an ocean voyage, touching at various 
ports, and sailing now east, now west. Fix the 
attention on a single bale of cargo, packed tight 
in the hold ; and, though the ship may have been 
tossed about in all directions by winds and waves, 
we are justified in saying that that particular bale 
of cargo has not moved during the long journey 
from port to port. Let the mate go down into 
the hold and disturb that bale from its place by 
one inch, and it has had in relation to the rest 
of the cargo a greater motion than it acquired 
during all the time that ship and cargo were 
voyaging together ; the disturbances that were 

1632] THIRD "DAY" 253 

common to all had no visible effect inside the 

No objections to the hypothesis of the earth's 
rotation being found tenable, it is shown by Salviati 
how much more simple is the real motion proposed 
than the supposition that the universe revolves 
daily round a fixed earth. " To make the universe 
revolve/ 1 he says, " in order to maintain the immo- 
bility of the earth is as little reasonable as to 
require, in order to see Venice from the top of 
the Campanile, that the whole panorama should 
move round the spectator instead of his simply 
moving his head." 

The primitive notion of the stars as fixed in 
a crystal sphere had been long overthrown. And, 
supposing accordingly that the stars were distinct 
and independent bodies, it was difficult to imagine 
laws controlling their motion about a fixed earth 
that should result in revolutions timed uniformly 
for all and at the same time of enormous rapidity. 
Salviati makes the improbable to be practically 
impossible by referring to the phenomenon now 
known as the "precession of the equinoxes," in 
virtue of which the direction of the earth's axis 
in space moves slowly, completing a revolution 
in about 26,000 years. The system of stellar 
motions that would be necessary to account for 
this would be inconceivably complex. 

A great part of the third "Day" is devoted 
to the question of stellar parallax. In this lay 
one of the most serious difficulties of the Coperni- 
can theory. If it was true that the earth swept 
round the sun in a circular orbit some two hundred 


millions of miles in diameter, then it must follow 
that at one time of the year we should get an 
entirely different view of the arrangement of the 
stars from that obtained six months earlier or later 
when the earth was at the opposite point of its 
orbit. The nearer stars should in fact undergo 
displacements in their apparent positions relative 
to those more distant The answer to this was 
that these displacements probably did take place, 
but were too minute to be detected. But this 
answer, though strictly true, implied that the 
distances of even the nearest stars were great 
beyond all comprehension ; and this in turn implied 
that the visible size of the stars indicated a real 
size of inconceivable dimensions. The latter diffi- 
culty was reduced by Salviati's assertion that the 
visible size of a star was an optical illusion ; the 
telescope showed the stars to be sharp points, in 
contrast to the planets which, though small to the 
eye, really did possess visible dimensions. But 
the former difficulty remained, and nearly two 
centuries passed before Bessel made the first rough 
measurement of a stellar parallax. His method 
was essentially that suggested in the dialogue 
by Salviati; though the results obtained indicated 
for the star 61 Cygni, a distance which would 
probably have astonished even Galileo himself. 1 

With the difficulties of stellar parallax still 
uppermost in his mind, Simplicio looks at the 
utilitarian side of the question, and remarks : 

" All this is very well, and it is not to be 

1 More recent measurements fix the distance of this star at about 
400,000 times that of the sun. 

1632] THIRD "DAY" 255 

denied that the heavens may surpass in extent 
the capacity of our imaginations, nor that God 
might have created them a thousand times larger 
than they are. But we ought not to admit 
anything to be created in vain, or useless in the 
universe. Now we see this beautiful arrangement 
of the planets disposed round the earth at distances 
proportioned to the effects they are to produce 
upon us for our benefit. To what purpose, then, 
should such a vast vacancy be afterwards inter- 
posed between the orbit of Saturn and the starry 
spheres, containing not a single star, and altogether 
useless and unprofitable? to what end? and for 
whose use and advantage ? " 

SALVIATI : " Methinks we arrogate too much to 
ourselves, Simplicio, when we assume that the 
care of us alone is the adequate and sufficient 
work and limit beyond which the Divine wisdom 
and power do nothing and dispose of nothing. 
I feel confident that nothing is omitted by God's 
providence which concerns the government of 
human affairs ; but that there may not be other 
things in the universe dependent on His supreme 
power, I cannot, with what power of reasoning 
I possess, bring myself to believe. So that when 
I am told of the uselessness of an immense space 
interposed between the orbits of the planets and 
the fixed stars, I reply that there is temerity in 
attempting by feeble reason to judge the works 
of God, and in calling vain and superfluous every 
part of the universe which is no use to us." 1 

SAGREDO: "Say rather that we have no means 
of knowing what is of use to us. I hold it to be 
one of the greatest pieces of arrogance and folly 
that can be in this world to say, because I know 

1 It is in the course of this discussion that Galileo says, "The 
space Comprised between Saturn and the fixed stars is, perhaps, 
occupied by invisible planets." The discovery of Uranus and Neptune 
has confirmed this conjecture. 


not what use Jupiter and Saturn are to me, that 
therefore these planets are superfluous. Nay 
more, that there are no such bodies in existence. 
To understand what effect is worked upon us by 
this or that heavenly body (since you will have 
it that all their uses must have a reference to 
us) it would be necessary to remove it for a while, 
and then the effect which I find no longer pro- 
duced on me, I may say depended on that body. 
Besides, who will dare to say that the space (called 
too vast and useless) between Saturn and the fixed 
stars is void of other bodies belonging to the 
universe? Must it be so because we do not see 
them? Then, the four Medicean planets and the 
companions of Saturn came into the heavens when 
we began to see them, and not before! And by 
the same rule the innumerable host of fixed stars 
did not exist before men saw them. The nebulae, 
which the telescope shows us to be constellations 
of bright and beautiful stars, were, till the telescope 
was discovered, only white flakes! Oh, presump- 
tuous! rather, oh rash ignorance of man." l 

Towards the end of the third "Day," reference 
is made to an annual rotation of the earth about 
an axis perpendicular to the plane of its motion. 
In ancient and mediaeval times a simple state of 
revolution of the earth round the sun would have 
implied a revolution in which the same side of 
the earth was always turned to the sun ; the 

1 Compare this with the "arguments" of Galileo's peripatetic 
opponents: "Animals that are capable of motion have joints and 
limbs ; the earth has neither joints nor limbs, therefore it does not 
move. The planets, the sun, and the fixed stars are all of one 
substance, that is to say, of the substance of stars ; therefore they 
either move together or stand still together. It is to the last degree 
unseemly to place among the celestial bodies, which are divine and 
pure, the earth, which is a sewer of filth." "Difesa di Scipione 
Chiaramonti," Florence, 1633. 

i6 3 2] THIRD "DAY" 257 

moon, according to this description, was said to 
revolve simply round the earth without any rotation 
of her own, which is not the way in which her 
motion would be described at the present day. 
Accordingly, in stating the earth to have a revolu- 
tion round the sun combined with a rotation about 
an axis, Copernicus would have implied that that 
axis continuously changed its position in space 
so as to be always in the same direction relatively 
to the sun. To indicate that as a matter of fact 
the position of the axis with regard to the sun 
varied, but remained the same with regard to space, 
Copernicus had to combine with his two chief 
motions a third one of annual rotation. 

This third rotation was therefore a complication 
only introduced by confusion in geometrical 
thought. That the actual state of things is quite 
simple is illustrated by Salviati by a reference 
to the motion of a ball floating in a basin of 
water. If the basin be held in the hand, the 
ball floating at or near the centre, and the 
experimenter turn round steadily on his feet, 
holding the basin in front of him, the ball 
remains in a position which is unaltered with 
reference to the walls and furniture of the room ; 
although with reference to the man supporting the 
basin, it might be said to have spun once com- 
pletely round. And so with regard to the annual 
rotation spoken of by Copernicus, Salviati says : 
"What other is the earth than a globe librated 
in tenuous and yielding air? That which you 
think to be a revolution in itself, you will find 
to be a not moving at all, but a continuing to 



be altogether immovable in respect of all that is 

It is here that he speaks so approvingly of 
the labours of his great English contemporary, 
William Gilbert of Colchester. 1 He explains 
Gilbert's theory of the earth as a huge magnet, 
and develops it, mentioning incidentally some 
observations and experiments of his own on 
magnetic phenomena notably on the increased 
power of magnets when suitably provided with 

The attractive and repulsive properties of 
magnets reminded Simplicio that in considering 
the causes of natural phenomena, some effects 
are attributed to sympathy which is an agreement 
and mutual appetency between things having the 
same qualities, while other effects are due to 
antipathy when things naturally repel and abhor 
each other. 

"And thus/' cuts in the wag, Sagredo, "with 
these two words they are able to give a reason 
for a great number of effects which we see, not 
without admiration, to be produced in nature. 
But it strikes me that this mode of philosophising 
is not unlike the style in which one of my friends 
used to paint. On his canvas he would write 
with chalk: here a fountain with Diana ahd her 
nymphs; here some harriers; in this corner a 
huntsman with a stag's head; the rest may be 
a landscape of wood and . mountain ; and what 
remains to be done may be put in by the colour- 

1 " I glorify," says Salviati, " I admire, and I envy this great author 
his marvellous conception of the earth as a magnet." Quite at the 
end of this " Day " Gilbert and his opinions are again referred to. See 

i633] FOURTH "DAY" 259 

man. Thus he flattered himself that he had 
painted the story of Acta&on, having contributed 
nothing towards it beyond the names!" 

The fourth "Day" of the Dialogue is devoted 
entirely to an examination of the cause of the 
tides, and is a development and extension of 
his letter on the same subject to Cardinal Orsini, 
1616. It is a singular circumstance that the 
argument, upon which Galileo mainly relied as 
furnishing a physical demonstration of the truth 
of the Copernican theory, rested on a misconcep- 
tion. The ebb and flow of the tides, he said, 
are a visible effect of the terrestrial double move- 
ment, since they are the combined result of (i) 
the earth's daily rotation, and (2) the inequality 
of the absolute velocities of the various parts of 
the earth's surface in its revolution round the 
sun. To this notion he attached capital importance, 
and he ridiculed Kepler's suggestion (which, 
however, was nearer the truth) that the attraction 
of the moon was in some way concerned in the 
phenomenon. That the influence of the moon was 
paramount had indeed been recognised in ancient 
times, but a scientific explanation in detail was 
not to be expected until the law of universal 
gravitation had been fully realised. 

This last part of the dialogue is therefore of 
little value, and may be passed over in considering 
the discussions of the first three "Days." The 
chief work of the dialogue was to establish the 
Copernican theory; which, first promulgated in 
the days when human vision was unaided, had 
been found by Galileo to be supported by all 


evidence that could be gathered by means of his 
new invention. The problem if it may be still 
said to exist takes a slightly different form at 
the present day. So far are we now from the 
pre- Copernican theory of a fixed earth, that we 
look upon no single object in the whole universe as 
fixed. The sun itself has its motion amongst 
the other visible stars ; the present direction and 
rate of that motion are roughly known. Accord- 
ingly, the alternative which offered itself to the 
controversialists of Galileo's day, that either the 
sun or the earth was stationary, does not concern 
us ; both of the bodies are moving. They move, 
however, in such a way that the motion of the 
sun is sensibly uniform, while the earth and the 
other planets can only be reasonably spoken of 
as travelling around him while he with his family 
of satellites is advancing through space. 

With this understanding as to what is meant 
when we speak of the sun, though not stationary, 
being the centre of the planets' motions, it need 
scarcely be mentioned that the Copernican theory 
has acquired, since the days of Newton, an enormous 
mass of evidence, which in a work of the present 
type it would be out of place to discuss. But 
whereas Copernicus and Galileo made it a question 
practically for common-sense to choose between 
the simple and the geometrically complex, 
dynamical evidence has now made any alternative 
to the simple explanation not only difficult but 
altogether beyond comprehension ; the main points 
of the Copernican doctrines are proved as 
absolutely as anything in science can be proved. 


This beautiful volume now so forgotten, of 
which we feel we have given an inadequate idea, 
is not simply a treatise on astronomical and 
physical science a powerful plea for Copernicanism 
in a country and at a time when all science was 
" vehemently suspected"; it is a book worthy 
of Socrates a book which ought to be studied 
by those who love free observation and experiment, 
free discussion and circulation of ideas in a word, 
freedom of thought, as the first essential to the 
progress of science and of our common humanity. 
In the words of Professor Play fair : 

"One forms a very imperfect idea of Galileo 
from considering the discoveries and inventions only, 
numerous and splendid as they are, of which he was 
the author. It is by following his reasonings and 
by pursuing the train of his thoughts in his own 
elegant though somewhat diffuse exposition of them 
that we become acquainted with the fertility of his 
genius with the sagacity, penetration, and com- 
prehensiveness of his mind. The service which he 
rendered to real knowledge is to be estimated, not 
only from the truths which he discovered, but from 
the errors which he detected not merely from the 
sound principles which he established, but from the 
pernicious idols which he overthrew. The Dialogues 
on the Two Systems are written with such singular 
felicity that one reads them at the present day, 
when the truths contained in them are known and 
admitted, with all the delight of novelty, and feels 
one's self carried back to the period when the 
telescope was first directed to the heavens, and 
when the earth's motion with its train of consequences 
was proved for the first time. Of all the writers 
who have lived in an age which was only emerging 
from ignorance and barbarism, Galileo has most 


entirely the tone of true philosophy, and is most 
free from the contamination of the time in taste, 
sentiment, and opinion/' 1 

* "Playfair's Dissertation," Supp. "Ency. Brit," 7th Ed. The 
Dialogues occupy the whole of vol. i. in Albert's edition of the Works 
of Galileo, 1842-56, and two- thirds of vol. vii. of Favaro's edition. An 
English translation was brought out by Thomas Salusbury in 1661. 




BY the beginning of January 1632, the printing of 
the Dialogues was so far advanced, that on the 3rd 
Galileo was able to inform his friend Cesare Marsili 
at Bologna that the work would be ready in ten 
or twelve days. It did not, however, appear till 
February. On the 22nd of that month Galileo 
presented copies to the Grand Duke (his former 
pupil) to whom the work was dedicated, and to 
other members of the Medici family. Next day he 
sent thirty-two copies to Marsili ; and had a number 
handsomely bound for friends and patrons in Rome, 
but they could not be despatched, owing to the con- 
tinued prevalence of the plague. Indeed, it was 
not till May that two unbound copies reached the 
Eternal City. One of these came into the hands of 
Cardinal Francesco Barberini (the Pope's nephew), 
who lent it to Castelli. . The latter writing to 
Galileo, 29th May, expressed his admiration for the 
work which surpassed all his expectations. 1 Shortly 
afterwards, Cohte Filippo Magalotti, Galileo's friend 

1 In a previous letter, 26th September 1631, the good Father vowed 
that when the book appeared he would read no others than it and his 


and, from his relationship to the Barberini family 
an influential personage, imported eight copies, and, 
at the author's request, presented one each to 
Cardinal Antonio Barberini, the Pope's brother; 
Niccolini, the Tuscan Ambassador ; Father Riccardi 
the Press Censor ; Mgr. Serristori, Counsellor of the 
Inquisition or Holy Office; and the Jesuit Father, 
Leon Santi. 

While these copies were being eagerly read in 
Rome, and passed from hand to hand, the book had 
been circulating in all parts of Italy, in spite of the 
obstacles to communication caused by the plague. 
The applause with which it was received by all men 
of independent minds was tremendous ; but in this 
paean of praise there was one solitary note of 
warning a note which would probably have been 
unheeded even if it came in time. Paolo Aproino, 
having read a MS. copy which Galileo had sent to 
Micanzio at Venice, begged his friend to write and 
advise the author to pause ere he printed a book 
containing such startling doctrines. Micanzio thought 
it better that Aproino should himself write, which he 
did on 1 3th March a month too late. Aproino s 
advice was to send MS. copies to the public libraries 
in the capitals of Europe, with permission for copies 
to be made by those who might wish to have them. 
This would prevent the dissemination of his revolu- 
tionary doctrines amongst the ignorant and ill- 
disposed who would only use them as a weapon for 
his destruction, while as to the enlightened and 
unprejudiced, no one would grudge the expense of a 
written copy of such a precious work. 

Great as was the applause on the one side, so on 


the other side was the consternation which the book 
created among the followers of the old school of 
thought. The educated world of Italy was then 
divided into two hostile camps that of Aristotle 
and Ptolemy on the one side ; and that of Coper- 
nicus, Galileo, and Kepler on the other. In the 
first were to be found blind worship of authority, 
and unquestioning adherence to ancient doctrine ; 
in the second, freedom of thought, research, recog- 
nition of demonstrated truths in a word, progress. 
As was to be expected, the first-named party was 
the most numerous and noisy, and it was reinforced 
by all those who opposed the innovators from 
interested motives. Foremost amongst these were 
the members of the Order of Jesus. They claimed 
for themselves the monopoly of instruction, and the 
first rank in the learned world, and were jealous of 
all intruders. Galileo was therefore in every way 
inconvenient to these people. Besides, had he not 
measured swords with distinguished members of the 
Order, as Fathers Scheiner and Grassi and (unfor- 
givable offence) had he not worsted them? And 
now his Dialogues appeared in which some old 
sores are re-opened ; this revolutionary book must 
be suppressed at all costs, and with it its detested 

Father Riccardi, the censor, was the first to 
announce the coming battle. One day early in 
August he remarked to Conte Magalotti, "the 
Jesuits will now persecute Galileo with the utmost 
bitterness." 1 It is important to establish this fact 
Scheiner in a conversation with Torricelli would 
* Letter, Magalotti to Guiducci, ;th August 1632. 


say little about the Dialogues, he found the digres- 
sions tedious (and no wonder, for some of them 
referred to himself), he did not wish to say much 
on the subject, but, he significantly added, "Galileo 
has treated me very badly." x Then Scheiner himself, 
writing to Gassendi of Paris, 23rd February 1633, 
says : 

"In these Dialogues the author has made null 
all my mathematical researches, and has laid violent 
hands on my ' Rosa Ursina,' on my discovery of the 
annual movement of the Sun-spots, and of that of 
the sun himself. I am preparing to defend myself 
and the truth." 2 

Before the date of his conversation with 
Magalotti just mentioned, it came to the ears of 
Riccardi, that some " ill-disposed persons 7 ' were 
trying to discover something in the book which 
could form the basis of an accusation against its 
author; they found something on the engraved 
title-page ! The words " Dialogo di Galileo Galilei, 
Linceo, al Ser. Ferd. II Gran. Duca di Toscana" 
are printed on the field of a pavilion, with the 
five palle or balls, the armorial bearings of the 
Medici, and surmounted by the Grand Ducal crown. 
Below, on the shore of a sea stand three persons 
disputing Aristotle, Ptolemy, and Copernicus, the 
two latter having their names printed on the edge 

1 Letter, Torricelli to Galileo, nth September 1632. 

s " The Rosa Ursina " was published in 1630, and was a fierce 
attack on Galileo personally. No direct answer was made, but in 
several passages in the Dialogues the book received some hard 
knocks, as Scheiner intimates in the above extract This Jesuit, if not 
the leader of the new crusade against Galileo, was certainly one of 
the foremost and most relentless of his enemies. For further proof of 
the complicity of the Jesuits, see pp. 284 and 342 infra. 

Title-Page of Dialogue of 1632. 

{To face p. 266, 


of their mantles. At their feet is the device of 
three dolphins, surrounded by a narrow band, 

bearing a motto and the monogram ^ B the whole 

being the business sign of the printer, G. B. Landini. 
This title-page was impugned as not having been 
submitted for ecclesiastical approval, and particularly 
they expatiated, with more malice than wit, upon 
the meaning of the three dolphins* device; it re- 
minded them so much of the three bees of the 
Papal arms ! It was a great relief to Riccardi's 
mind when Magalotti pointed out that the same 
device appeared on nearly all the works which 
issued from the Landini press at Florence, where 
also this book was printed. 

This shot, then, had not taken effect, and the 
" ill-disposed persons " had to find some other mode 
of attack. They now brought against the author 
the two-fold charge (i) that the preface was printed 
in different type from the rest of the book, which 
was true, but was simply a necessity of the printer ; I 
and (2) that some weighty arguments against the 
Copernican theory, which the Holy Father had 
brought forward in conversation with Galileo in 
1624, were not in the printed book, although it 
was a condition that they should be. This charge 
was not true, for the " weighty arguments " were in 
reality only one, and this, as we have seen, was 
duly introduced at the end of the work, where it 

1 After receiving the Imprimatur for Rome, and foreseeing no 
further difficulty, Galileo had begun to set up his book, and by i6th 
August 1631 about one-third of the volume was in print. Hence the 
preface, which went to press later, had to be printed on a separate 
sheet, and in different type. 


was appropriately put into the mouth of Simplicio, 
who gave it as an argument which he had from " a 
very eminent and learned personage " (p. 248 ante}. 
Foiled again, the assailants now fastened on 
the very natural circumstance that the " weighty 
argument" was placed in the mouth of Simplicio, 
the defender of Ptolemy. Knowing the Pope's 
weaknesses, vanity, arrogance, and ambition, 1 
they made him believe that by Simplicio the 
simpleton no other was intended than Urban 
VIII. himself! One would have thought this 
impossible with this shrewd old man (seeing the 
friendly relations which up to this had subsisted 
between him and Galileo), but it is beyond all doubt 
that it was so, and it put his Holiness in a terrible 
rage. While in this condition they easily per- 
suaded him that the Copernican doctrine ran 
counter to the dogmas of the Catholic faith, and 
after this it was not difficult for them to show that 
the Dialogues, which were a defence of that 
doctrine under a flimsy veil, would do incalculable 
injury to the Church. Having thus worked on the 
Pope's fears, they easily persuaded him that in this 
work Galileo had again, though under concealment, 
dared to interpret the Scriptures ; he was therefore 
rebellious ; and he was further deceitful in that he 
obtained the Imprimatur by cunning devices. 

1 He wished to be thought another Leo X. So vain was he that 
he caused documents to be forged proving his family to be one of the 
oldest and most noble of the Florentine stock. He is noted in history 
for three things : (i) excommunication of all who took snuff in churches, 
1624 j (2) persecution of Galileo, 1632-42 ; and (3) the foolish 
campaign against the Duchy of Castro, "Guerra di Castro," 

1 633] PLAN OF CAMPAIGN 269 

Although the safety of the Church and the 
vindication of its decrees were the ostensible 
reasons for the subsequent proceedings against 
Galileo, it would not be far from the truth to say 
that revenge for an assumed personal insult was the 
primary and determining factor. 1 Without this 
personal motive the storm may have blown over as 
other and equally threatening ones had previously 
done. Urban VIII. and many of the high 
dignitaries of the Church were, if anything, 
Copernicans (they certainly were not Ptolemaists, 
and hardly even peripatetics), 2 while others were 
indifferent and cared little one way or the other. 
As regards the Pope himself, we have seen his 
letter of soth April 1613, to Galileo, praising so 
highly the book on Sun-spots the very work on 
which the prohibition of 1616 was based. We 
have also seen how delighted he was with " II 
Saggiatore" and the " Reply to Ingoli," in both of 
which the Copernican theory is defended ; and, 
finally, we have Urban's own statements (i) that 
the Copernican doctrine is not heretical, but only 
rash, and (2) that if it rested with him, the decree 
of 1616 would never have been issued. All this 
seems to show that, if the question of a personal 
insult had not arisen, the Dialogues might have 
weathered the storm, or, at the worst, been put on 
the Index, as was the book of Copernicus in 1616, 
" until corrected." 

While these things were passing secretly at 

1 See Galileo's letter to Micanzio, dated 26th July 1636, where he 
says the making game of the Pope, as his Holiness had been 
persuaded, was the primary cause of all his troubles. 

2 See Alberi, vol. xvL p. 326. 


Rome, Galileo in Florence gave himself up to 
unmixed delight at the great success of his book. 
His friends, such as Castelli, Cavalieri, Micanzio, 
Campanella, and others, expressed in letters their 
unbounded admiration. Thus, Micanzio, writing 
on 3rd July, says : 

"I had hardly time to devour your book when 
it was taken from me and lent from one to another. 
To-day, no sooner do I get it back by main force, 
than I am obliged to send it to the Commissary 
Antonini at Verona, one of our cleverest men, and 
one who admires you above all the literati of the 

Not one of all his friends who praised the book 
so highly had any foreboding that it was soon to 
bring its grey-headed author before the bar of the 
Inquisition, and least of all Galileo himself. He, 
of course, expected the usual opposition from his 
" scientific " opponents, and was prepared to meet 
it ; but he considered himself secure from anything 
like conflict with the ecclesiastical authorities. 

One day, about the middle of August, the first 
thunder-clap broke over Galileo. His publisher 
Landini received instructions, though for the time 
only provisional, forbidding the further sale of the 
Dialogues. 1 The second clap, which followed in a 
few days, was the news of the appointment of a 
special commission at Rome by order of the Pope, 
and under the presidency of his nephew, Cardinal F. 
Barberini, to examine the book and report. It was 
composed of Jesuits, Dominicans, and Theatins, 

1 It appears this step was taken on the report of the Jesuit Father 
Inchofer, one of the counsellors of the Inquisition. 


" not one of whom had any knowledge of mathe- 
matics, or familiarity with abstruse speculations/ 1 
all endeavours of Niccolini and others to get friends 
of Galileo, such as Castelli and Campanella, put on 
the board being vetoed by the Pope. 1 Galileo now 
appealed to his Sovereign for protection, and, on 
24th August, the chief Secretary Cioli wrote to 
Niccolini that the Grand Duke was greatly 
surprised to learn that a book which had been laid 
before the supreme authorities at Rome by the 
author in person ; had been carefully read there 
again and again, as well as afterwards at Florence ; 
had, at the author's request, been altered by these 
authorities "as seemed good to them" ; and finally 
had received the Imprimatur for Rome and 
Florence, should now, after two years, be considered 
suspicious, and be prohibited. His Highness was 
of opinion that this opposition must be directed 
against the person of the author rather than against 
his book, so often and so carefully read and revised 
by the proper authorities. In order, then, to inform 
himself of the merits or demerits of his servant, his 
Highness desires that that which is granted in all 
disputes and before all tribunals should be permitted 
to the accused, viz., to defend himself against his 
accusers. The Grand Duke, therefore, requests 
that the accusations may be sent to Florence, so 
that the author, who stands firmly on his innocence, 
may see and answer them. 2 

On the same day on which this despatch left 

1 See letters of Campanella to Galileo, dated 3ist August and 
25th September 1632, 

2 The original draft of this despatch, much of which is in Galileo's 
handwriting, is now in the National Library, Florence. 


Florence a mandate was issued from Rome, con- 
firming the provisional prohibition of the Dialogues, 
and ordering Landini to send all copies in stock 
to Rome. He replied that the edition had been 
sold out, and, consequently, he had no copies to 

On receipt of the Grand Duke's orders, Nicco- 
lini hastened to carry them out, but met with 
more opposition than either he or his master had 
expected. The Pope received him in such a way 
that he thought the world must be going to pieces, 
and at the first mention of Galileo's name the 
Holy Father interrupted him bluntly : " Your 
Galileo has dared to meddle with things that he 
should have left alone in fact, with the most im- 
portant and dangerous subjects that can be stirred 
up in these days." On the Ambassador remarking 
that the book was published with the approbation 
of the Church, the Pope angrily replied that both 
Galileo and his secretary, Ciampoli, had deceived 
him on that matter. The censor, Riccardi, had 
also deceived him, "but," he added, "the latter 
had been himself deceived, for he had been in- 
duced by fair speeches to approve the book, and 
by more fair speeches to allow it to be printed in 
Florence." Thinking to save the book from con- 
demnation, Niccolini hinted that it was dedi- 
cated to the Grand Duke. " What of that ? " was 
the reply, "I have prohibited books which bear 
my own name on the title-page." The Pope 
added, "in charging a special commission to ex- 
amine the book, instead of handing the affair at 
once to the Inquisition, I have followed a course 


best for Galileo's interests he who did not fear 
to make game of me." Niccolini then begged 
that the accused may know the charges against 
him and have an opportunity of justifying him- 
self, to which Urban curtly answered : '* Galileo 
knows well enough in what way he has trans- 
gressed. In these matters of the Holy Office 
nothing is ever done but to pronounce judgment, 
and then summon to recant" 1 

Two letters from Magalotti, who was usually 
well informed, arrived at the same time as this 
despatch, both dated 4th September, one to 
Mario Guiducci, the other to Galileo. Magalotti's 
news was on the whole reassuring. From the 
opinions of persons present at the sittings of 
the commission, he thought he could say that 
matters would not, go so far as condemnation of 
the Copernican doctrine " by supreme authority." 2 
He thought with Riccardi that they would not 
entirely prohibit the Dialogues, but only " correct" 
them, so as to sustain the decree of 1616. He 
advised (as Niccolini also had done) the utmost 
patience and circumspection, and to confer with 
Cardinal F. Barberini rather than with the Pope 
himself, "for reasons which it is not necessary to 

The special commission, after a month's session, 

1 Letter, Niccolini to Cioli, $th September 1632. Here the Holy 
Father shows his hand, Galileo dared to make game of him. The 
poison had taken effect 

2 It never did, in fact, come to this ; for the "supreme authority" 
is the Pope speaking ex Cathedra^ or an (Ecumenical Council. The 
proceedings of 1616 were not endorsed by "supreme authority," 
and we shall find this to be the case in the present proceeding's 



submitted a long report to the Pope. The docu- 
ment begins with a statement of the course of the 
negotiations for the printing of the Dialogues, and 
then come three indictments against the author : 

1. Galileo had transgressed orders in deviat- 
ing from the hypothetical standpoint, by maintain- 
ing decidedly that the earth moves and that the 
sun is stationary. 

2. He has erroneously ascribed the phenomena 
of the tides to the stability of the sun and the 
motion of the earth, which are not true. 

3. He has been deceitfully silent about the 
command laid upon him in 1616, viz., to re- 
linquish altogether the opinion that the sun is 
the centre of the world and immovable and that 
the earth moves, nor henceforth to hold, teach, 
or defend it in any way whatsoever, verbally or in 

Then follows the remark : "It now remains to 
be considered what proceedings are to be taken 
against the person of the author, and against his 
printed book." The rest of the document is taken 
up with an elaboration of the charges against 
Galileo, and a fuller account of the negotiations 
for the Imprimatur. These need not detain us; 
but in a final clause, Galileo is specifically charged 
with having transgressed the order of the Holy 
Office to relinquish (etc., as per charge (3) above). 
This, then, was his chief offence; the others 
"could be corrected if the book was thought to 
be of any value " ; but to deliberately and deceitfully 
transgress commands, that, evidently, could not be 
" corrected" or condoned. 


Here for the first time the minute of 26th 
February 1616 is mentioned, as to which Niccolini 
has something of importance in his despatch of nth 
September to Cioli. Reporting an interview with 
the Master of the Sacred Palace, he says that 
Riccardi, after advising patience and caution, re- 
peated the old stock complaints, that the Dialogues 
imperilled the faith, that the author did not confine 
himself strictly to mathematics, but brought under 
discussion religion and the Scriptures [which is not 
true], and that the Papal orders as to the preface, 
end, and hypothetical treatment had not been com- 
plied with an extraordinary assertion for one who 
had himself certified that they had been complied 
with. He then confided to the Ambassador as a 
profound secret "that it had been discovered in the 
books of the Holy Office that sixteen years ago (it 
having been heard that Galileo entertained that 
opinion, and disseminated it in Florence) he was 
summoned to Rome, and forbidden by Cardinal 
Bellarmine, in the name of the Pope and the Holy 
Office, to hold that opinion. And this alone is 
enough to ruin him entirely/ 1 Evidently the paper 
here hinted at is the minute of 26th February 1616. 
It will, therefore, be desirable to pause for a 
moment, and read again our remarks on p. 166, 
for our account so far of these new proceedings 
brings out a point there discussed, which we wish 
to emphasise, viz. that the minute is not true to 
the spirit of the proceedings. We have seen that 
the Pope knew all about the process of 1616 in 
fact, as Cardinal Maffeo Barberini, was an unwilling 
party to it. If Galileo was then commanded to 


relinquish altogether his opinion, and henceforth 
not to hold, teach, or defend it in any way what- 
soever, verbally or in writing, why did Urban VIII. 
discuss this same opinion with him in 1624? why 
did he openly approve "II Saggiatore" and the 
tl Reply to Ingoli " ? and why in 1630, when Galileo 
took his Dialogues to Rome, was he not met with 
a non-possumus, and referred back at once to this 
rigid prohibition ? Clearly, because this rigid pro- 
hibition had for him no existence had no right to 
exist, for he knew it was not intended that Galileo 
should be forbidden to hold, teach, or defend his 
opinion in any way whatsoever, verbally or in 
writing, except in case he refused to be bound by 
Cardinal Bellarmine's simple admonition a con* 
tingency which did not arise. The minute, there- 
fore, is not true to the spirit of the proceedings, 
and should properly be treated as non-existent. It 
is, moreover, of no value in law in that it bears 
no signatures. To base, then, a charge against 
Galileo on such a worthless paper convicts his 
persecutors of ultra vires, and shows their de- 
termination to punish him at any price, even at 
the cost of a judicial crime. 1 

Now let us return to our narrative. A few days 

1 The steps of these new proceedings are also against the theory 
of a forgery with ulterior designs. Were it so, why, during the long 
and vexatious negotiations about the Imprimatur^ did not the forgers 
appeal to it at once, as a bar to granting a licence ? Why, immediately 
on the appearance of the book, did they not accuse Galileo of break- 
ing his solemn promise, and call down upon his head the penalty for 
disobedience with which the document threatened him ? Why have 
recourse for months to trumpery charges and ignoble stratagems, 
when they could have played this trump card ? Clearly, because its 
existence was not known to them until the first week in September 
1632, when its discovery was a surprise to all, friends and foes alike. 

i6 3 3] SUMMONED TO ROME 277 

after Niccolini's interview with Riccardi, on the 
1 5th September, the Pope sent word to the 
Tuscan Ambassador that Galileo's affairs would 
be handed over to the Inquisition. At the same 
time the strictest secrecy as to this step was 
enjoined on both the Grand Duke and Niccolini, 
with a hint that otherwise they would be pro- 
ceeded against, according to the statutes of the 
Holy Office. Niccolini, astounded by this inti- 
mation, hastened to the Pope to avert, if possible, 
the danger of a trial, but his pleadings were in 
vain. Urban was good enough to say that Galileo 
was still his friend, but his opinions had been 
condemned sixteen years before, and were in the 
highest degree pernicious to the Church. On 
23rd September the following order was issued: 

"His Holiness charges the Inquisitor at Florence 
to inform Galileo, in the name of the Holy Office, 
that he is to appear in the course of the month 
of October, in Rome, before the Commissary- 
General. He must obtain a promise from Galileo 
to obey this order, which the Inquisitor is to de- 
liver in the presence of a notary and witnesses, 
but in such a way that Galileo shall know nothing 
of their presence, so that if he refuse to obey 
they may bear witness to his contumacy/' 

This order, which was delivered to Galileo on 
ist October, and with which he consented in 
writing to comply, fairly overwhelmed him, for, 
from the secrecy maintained in Rome, he was 
wholly unprepared for any such measure. Scarcely 
recovered from a complaint in the eyes which had 
lasted several months, suffering otherwise in health, 


and at an advanced age, he was now to go to 
Rome in the midst of the plague (which had 
broken out afresh) to appear before the terrible 
Inquisition. No wonder that he was dismayed, 
and that in spite of his promise "willingly to 
obey the order in the course of this month, 
October," he made every effort to evade it His 
deep depression is evident from a long and 
pitiable letter, of i3th October, to Cardinal 
Francesco Barberini (the Pope's nephew), sent 
through the hands of Niccolini : 

" That my Dialogues recently published should 
find adversaries was not to be doubted, as your 
Eminence no doubt foresaw, It is in general the 
lot of all opinions which in one way or another run 
counter to the accepted doctrines. From the recep- 
tion of my other works I expected as much, but 
what I did not expect was that the hate of one or 
two of my enemies (furious at seeing the lustre of 
their works tarnished by mine) would be able so to 
influence my superiors as to make them believe that 
my works are unworthy of the light of day, and 
should be stifled. The prohibition of the printing 
and sale of my Dialogues has been a cruel blow to 
me, but I am consoled by the knowledge of the 
extreme purity of my conscience, and by the feeling 
that I shall have no difficulty in justifying my 

" I will not conceal from your Eminence that the 
injunction to present myself without delay before 
the tribunal of the Holy Office has afflicted me 
profoundly. It is impossible to think without 
bitterness that the fruits of my labours and studies 
for so many years (which gave to my name in the 
scientific world a certain tclai) should now be 
branded as criminal. All this depresses me to such 


an extent as to make me curse the time I have 
devoted to these labours yes, I regret having 
given to the world so much of my results. I feel 
even the desire to suppress, to destroy for ever, to 
commit to the flames, what remains in my hands. 
Thus I should satisfy the burning hate of my 
enemies. These are some of the thoughts which 
afflict me, and increase the burden of my seventy 
years ; they aggravate my numerous physical 
sufferings, and cause me persistent insomnia. 
When to these is added a journey, rendered 
more painful and dangerous by sundry causes, I 
am almost certain that I shall not reach the end 
alive. The desire to live, common to all men, 
makes me implore the intercession of your 
Eminence, encouraged thereto by the kindness 
of heart which distinguishes you, and of which 
I as well as others have been the recipient. I 
beg you, then, to represent to the Holy Father my 
present pitiable situation. . . . 

"Whether it be necessary to receive my 
justification in writing, or by viv& voce, I would 
point out that there are here in Florence the 
Inquisitor, the Archbishop, and other learned 
functionaries of the Church, who would be able, 
it seems to me, to decide graver causes than mine, 
and before whom I am ready to appear. It is 
hardly likely that in a book, which has been 
carefully examined by the censors, with full power 
to omit, to add here, to correct there, there should 
still remain errors so grave that their correction, 
or the punishment due to them, should be beyond 
the power of the local authorities." l 

Before taking action the Ambassador consulted 

1 By the same post Michelangelo, the younger, wrote to the same 
Cardinal, entreating him, out of consideration for the philosopher's 
age and infirmities, to try all means to have his affairs settled in 
Florence. See letter dated I2th October. 


Castelli (whom the Grand Duke had appointed as 
his counsel in this affair) as to the advisability of 
delivering Galileo's letter to the Cardinal. It was 
decided to do so, and Niccolini reported that it was 
received in a very friendly way, with assurances of 
his Eminence's kindly disposition towards the 
writer. The letter was discussed by the Holy 
Office on nth November, in presence of the Pope; 
but his Holiness would not grant the prayer, and 
ordered that the writer must be compelled to come 
to Rome. Niccolini was unwearied in trying to 
get the affair settled in Florence, but to no purpose. 
The Pope had seen Galileo's letter of I3th October, 
but the journey to Rome could not be dispensed 
with. "Your Holiness," exclaimed Niccolini, " in- 
curs the danger, considering Galileo's age, of his 
being tried neither in Rome nor in Florence, 
for I solemnly assure your Holiness that he may 
die on the way under all these difficulties and 
anxieties/' " He can come very slowly/' replied the 
Pope, " in a litter, with every comfort, but he really 
must be tried here in person. And may God 
forgive him for having been so deluded as to in- 
volve himself once more in these difficulties, after 
having been extricated by me from his first 
difficulties in 1616, when I was Cardinal." Much 
discomfited and with profound sorrow, Niccolini 
communicated this decision to Galileo in a letter on 
1 3th November, and in a despatch to Cioli of the 
same date. 

A few days later, igth November, Galileo was 
summoned before the Inquisitor at Florence, in 
accordance with the Papal orders, and was charged 

i6 3 3] SAD STATE OF HEALTH 281 

to comply with the mandate to go to Rome in the 
presence of a notary and two witnesses a respite 
of one month being allowed. The appointed time 
had nearly arrived and no preparations had been 
made for starting. The Inquisitor sent his vicar to 
see Galileo and reported the result in a letter to 
Rome on i8th December: 

"My vicar found Galileo in bed ; he was quite 
ready to set out, but in these times he had no heart 
for it ; besides, just now, owing to a sudden attack 
of illness he was not in a condition to travel. He 
has sent me the enclosed medical certificate, so that 
I have not failed to do my duty," 

The certificate, dated i/th December, gives an 
idea of the physical sufferings of this much-tried 
man, and is signed by three doctors : 

"We, the undersigned physicians, certify that 
we have examined Signer Galileo Galilei and find 
that his pulse intermits every three or four beats, 
from which we conclude that his vital powers are 
affected, and at his great age much weakened. To 
the above are to be ascribed frequent attacks of 
giddiness, hypochondriacal melancholy, weakness of 
the stomach, sleeplessness, and flying pains about 
the body, to which others also can testify. We 
have also observed a serious hernia with rupture of 
the peritoneum. All these symptoms are worthy of 
notice, as under the least aggravation they might 
become dangerous to life." 

Little importance seems to have been attached 
to this certificate at Rome. Niccolini (26th 
December) fears that the ecclesiastical authorities 
at Florence will be ordered to take extreme 


measures. Castelli (2 5th December) urges his old 
and revered master to set out. But in this, as 
in all his letters of this period, he shows that 
he had no idea of the real nature of the pro- 
ceedings going on. Knowing of no crime 
committed by his master against the Holy Office, 
he urged him to set out, because he had the 
idea that Galileo's persecutors desired nothing 
better than that he should refuse, in order that 
they may decry him as an obstinate rebel against 
Holy Church. 

On 3oth December the fears of Niccolini 
were realised. On that day a Papal order was 
issued to the Inquisitor at Florence, stating that 
neither his Holiness, nor the Congregation of 
the Holy Office, could or would tolerate further 
evasions. It must, therefore, be proved that 
Galileo's state was really such that he could not 
come to Rome without danger to his life. A 
commissioner with a physician would be sent to 
Florence, who would see Galileo and make a 
true and trustworthy report on his condition, 
and if he were in a state to travel the commissioner 
must bring him a prisoner in chains. If out of 
consideration for his health, or other danger to 
life, his coming must be postponed, then as soon 
as he had recovered, or the danger was over, 
he was to be brought a prisoner in irons. The 
commissioner and physician would travel at Galileo's 
expense, because he had not obeyed the command 
to appear when his condition would have per- 
mitted it. 

To avert these extreme measures the Grand 


Duke caused Galileo to be informed (nth January 
1633) that it was at last necessary to obey the 
orders of the supreme authorities at Rome, and 
in order that he might perform the journey more 
comfortably Grand-ducal litters and a trustworthy 
guide would be placed at his disposal ; he would 
also be lodged in Rome in the house of the 
Grand Duke's Ambassador. The pitiful impotence 
of an Italian ruler of that day in face of the 
Roman Church is painfully obvious in this decision. 
The Sovereign does not dare to protect his subject 
more, his old and respected tutor, and the 
greatest philosopher of whom Italy could boast 
but gives him up to the dreaded Inquisition, as 
if he were an alien malefactor. The Venetian 
republic was the only State in Italy that would 
have asserted its independence (as it had often 
done before), and would have refused to hand 
over one of its officials to the Roman power. 
Indeed, when these proceedings began, Francesco 
Morosini of Venice offered to reinstate Galileo 
in his old chair at Padua on any conditions that 
he chose to make, and to print his Dialogues in 
Venice, Galileo was now suffering a bitter penalty 
for the mistake of 1610 in deserting Padua. 1 

2Oth January 1633 was the day fixed for 
Galileo's departure. On the I5th he addressed 
a long letter to his friend Elia Diodati of Paris, 
a celebrated jurist and advocate. It begins with 

1 This old friend of Galileo was a power in Venice. Francesco 
Morosini, the son, was the famous Captain-General of the Republic 
arid conqueror of the Morea in the war against the Turks 1684^94 ; 
hence his name in history, II Peloponesiaco, He was elected Doge 
in 1688, and died fighting at Nauplia in 1694, aged seventy-six. 


comments on the astronomical treatises of Morin 
and Fromond which Diodati had sent him. He 
then goes on to speak of his own unhappy 

" Many years ago when the stir about Copernicus 
was beginning, I wrote a letter [to the Grand- 
Duchess Cristina], in which, supported by the 
authority of numerous Fathers of the Church, 
I showed what an abuse it was to appeal so 
much to Holy Scripture in questions of natural 
science. As soon as I am in less trouble I will 
send you a copy. I say in less trouble, because 
I am just now going to Rome, whither I have 
been summoned by the Holy Office, which has 
already prohibited the circulation of my Dialogues. 
I hear from well-informed persons that the Jesuit 
Fathers have insinuated in the highest quarters 
that my book is more execrable and injurious to 
the Church than the writings of Luther and 
Calvin. . . . 

"My publisher is disconsolate, the prohibition 
of the book has caused him a loss of more than 
2000 scudi, for the sale of the first edition and 
a second twice as large was assured. As for 
myself, in the midst of so many afflictions and 
embarrassments that which afflicts me most is 
the thought that I must renounce my other works 
especially my work on Motion or at most, that 
I cannot hope to see them appear during my 

On 2Oth January, this man of woes set out on 
his terrifying journey in a Grand-ducal litter. How 
different the circumstances from those of the 
same journey eight years before! Prince Cesi, 
his entertainer at Acquasparta, was dead ; his own 
health, never good for many years past, was now 

1633] JOURNEY TO ROME 285 

a chronic cause of suffering ; and his eyesight 
had begun to fail. Not only was the time of 
year unfavourable (January February being the 
season when the biting tramontana is most 
frequent), but the country through which he had 
to pass was bleak and inhospitable, and its in- 
habitants, always wild as the winds that howl 
across its wastes, were now made more wild and 
desperate by the ravages of the plague. At the 
frontier post, Ponte Centino, he was obliged to 
halt twenty days on account of quarantine. From 
each halting place the poor old man had written 
to his daughter, the one soul on earth to whom 
he knew he could turn for sympathy and consola- 
tion, and she, sweet consolatrix, what can she 
say in reply? After expressing her grief at his 
being detained so long in a wretched habitation, 
deprived of every comfort, she entreats him "to 
keep up his spirits, and to put his whole trust in 
God, who never forsakes those who trust in Him." 
What else could she say ? although at the moment 
she knew that some of God's ministers on earth 
were intent on his persecution for the greater 
honour and glory of His kingdom. 

On the afternoon of i3th February Galileo 
arrived in Rome and was warmly received at 
the Tuscan Embassy. On the next day Niccolini 
informed the Grand Duke of his arrival, and that 
next morning he would introduce him to Cardinal 
F. Barberini, and beg that he be permitted to 
remain at the Embassy instead of being locked up 
in the prison of the Holy Office. This favour was 
at once granted provisionally, and afterwards 


officially confirmed, with injunctions to keep in- 
doors, and to see no one until further orders. 
Beyond this, and to Galileo's surprise, no official 
notice was taken of his presence for some time. 
Writing to Cioli on igth February, he says : 

"As to the situation of my affairs I can tell 
you nothing. However, to judge by what has 
passed, it appears to me, as well as to the 
Ambassador and his staff, that the storm which 
menaces me is a little calmed at least in appear- 
ance, so that I do not give way to discourage- 
ment, as if shipwreck were inevitable, and all 
hope of reaching port were gone the more so as 
following the instructions of my master, Ariosto : 

' I make sail with modesty 
Amidst the raging billows. 7 

"I keep to the house, not thinking it proper 
to go out as if I wished to show myself. Up 
to the present no official steps have been taken. 
One of "the members of the Congregation has 
called on me twice, conversing in the most agree- 
able manner, and giving me an opportunity to 
explain myself, and to show my submission, always 
sincere, to the Church to which, as far as I could 
see, he listened with satisfaction. If his visits, as 
may be supposed, were made with the knowledge 
or even by order of the Congregation, I may con- 
sider them as the beginning of a milder treatment, 
far removed from the cords, chains, and dungeons, 
with ^ which I was menaced. I find another con- 
solation in the kindly sentiments towards me ex- 
pressed by many influential personages. As it 
appears to^ me easier to confirm the latter in their 
good opinions than to convert those who are un- 
favourable, I think, with the Ambassador, that 
letters from our august master to Cardinals Scaglia 

i6 33 ] HOPES AND FEARS 287 

and Bentivoglio l would be very useful, and if you 
agree with us I beg that you will obtain me this 

The member of the Congregation here referred 
to was Mgr. Serristori. Niccolini thought that 
the object of his visits was to discover the present 
sentiments and defensive arguments of the dreaded 
dialectician, and was inclined to think that they 
boded well. 

" I think," he writes, " I have succeeded some- 
what in cheering up the good old man by what 
I have told him of the steps being taken in his 
favour. But he constantly expresses his wonder 
at all this persecution." 2 

The same cheerful confidence is expressed in 
Galileo's letter of 25th February, to Bocchineri: 

"The Ambassador thinks he perceives each 
day a diminution in the irritation against me, and 
so does Father Castelli, who is for me a zealous 
and indefatigable advocate. We learn, in short, 
that the many and serious accusations against me 
are reduced to one, and that the others have been 
allowed to drop. Of that one I shall be able 
to clear myself without much trouble, when the 
grounds of my defence have been heard. Little 
by little I am bringing these to the ears of some 
of the higher officials, who can neither refuse 
absolutely to listen to my explanations, nor to 
leave them entirely without reply. S6 we con- 
clude that in the end a favourable issue may be 
hoped for. 

" I keep strictly t6 the house which appears 
to me and my friends to be the correct thing. 
The Cardinal Barberini has given me the same 

1 Bentivoglio was a pupil and disciple of Galileo in Padua. 

2 Despatch to Cioli, I9th February 1633. 

288 THE INQUISITION [ r63 2- 

counsel, not ex officio but, as he says, as a friend. 
As I have already told you, not a word official 
has yet come from the tribunal. One of the 
counsellors, my friend and protector for many 
years, has visited me a couple of times and 
furnished me an occasion to explain myself freely 
on several points, and to show him some papers 
drawn up by me for this case, with which he 
declared himself satisfied. 1 We suppose, not with- 
out reason, that these visits have been made with 
the knowledge, and, perhaps, even by order of the 
superior authorities, with the object, perhaps, of 
getting some general information. If so, they could 
not have adopted a better course in my interests. 

" The deprivation of exercise for the last forty 
days begins to be prejudicial to me, for as you 
know I find exercise necessary for my health. My 
digestion especially is troubled ; viscous matters 
accumulate ; and for the last three days painful 
twitchings in the limbs have prevented my sleeping. 
I hope that a severe ^dietetic regimen will effect 
a cure. Some days ago I told you how useful 
would be letters from his Highness to Cardinals 
Bentivoglio and Scaglia, who, as I am privately 
informed, are well disposed towards me. If we 
find in the Congregation one or two members 
ready and resolute to defend innocence and the 
truth, we may hope that their voices will suffice 
to impose silence on those inipiically inclined. 
Therefore I beg you to procure these letters 
through the medium of Signor Cioli. 

U P-S. Please communicate this letter to my 
daughters and Vincenzio." 

Niccolini's despatch to Cioli of two days later 

1 For what was probably Galileo's line of defence at this time, see 
Favaro's "Nuovi Contributi alia Storia del Processo di Galileo" 
(Atti del R. Istituto Veneto, 1894-95), an admirable piece of con- 
structive evidence. 


(2 yth February) explains the nature of this chief 
accusation : 

" Although I am unable to say precisely what 
stage Galileo's affairs have reached, or what may 
happen next, as far as I can learn the main difficulty 
consists in this these gentlemen maintain that in 
1616 he was commanded neither to discuss the 
question of the earth's motion, nor to converse 
about it. He says, on the contrary, that these 
were not the terms of the injunction, which were 
that that doctrine was not to be held or defended. 
He considers that he has the means of justifying 
himself, insomuch as it does not at all appear from 
his book that he does hold or defend the doctrine ; 
or that he regards it as a settled question, as he 
merely adduces the reasons kino inde. The other 
charges appear to be of less importance and easier 
to get over." 1 

On the same day the Ambassador in a long 
audience officially announced Galileo's arrival, and 
expressed the hope that his Holiness would now 
be convinced of his reverence for things spiritual, 
especially in reference to the matter in hand. The 
Pope replied that he had shown Galileo a special 
and unusual favour in allowing him to stay at the 
Ambassador's house instead of remitting him to 
prison. Niccolini suitably acknowledged the great 
favour, and then went on to urge that in considera- 
tion of Galileo's age and bad health the trial may 
be hastened Urban replied that the proceedings 
of the Holy Office were usually tedious, and he 
really did not know whether so speedy a termina- 
tion could be looked for. They were still engaged 
with the preliminaries. 

1 See remarks on this point, p. 274 ante. 


As to the nature of these preliminaries nothing 
certain could be learnt, but Galileo continued to 
hope for the best. In a letter to Geri Bocchineri 
(5th March), after acknowledging receipt of the 
letters for Cardinals Bentivoglio and Scaglia which 
had, as he thought, a good effect, he goes on to 
say : 

"As to my affair, it goes on silently as from 
the first day. If one can judge by rare signs, 
the accusations have lost much of their gravity, 
and already some have been entirely dropped by 
reason of their evident insignificance, which is a 
good presage for those that remain/* 

A fortnight later, on igth March, he wrote 
in a similar strain to Cioli : 

"The same silence continues to be observed 
in my affair, and nothing more can be ascertained 
than what the Ambassador has picked up here 
and there, and which is sufficiently vague. My 
indefatigable defender, Benedetto Castelli, has also 
been secretly informed, but in the same general 
terms, that the proceedings have taken a slightly 
more favourable turn, thanks to the letters of 
his Highness. Therefore, as the Ambassador 
will tell you, the same intervention with the 
other Cardinals, members of the Congregation, 
would be of great utility, the two to whom letters 
have already been addressed having expressed 
themselves in this sense. I pray you then to 
obtain for me from his Highness this additional 

In spite of the gravity of the situation, it 
would seem that Galileo was careful to write to 
his daughter in such a strain as to calm her 


anxiety throughout this weary time. Therefore, 
on 1 3th March, she writes back: 

"As matters are going on so favourably I 
will not mind though your return be delayed, for 
indeed my being disappointed is a small thing, 
if staying where you are redounds to your 
reputation and advantage ; and what makes me 
still more easy is to hear how honourably you 
are treated by those excellent gentlemen, and in 
particular by her Excellency the Ambassadress. 
I am well now because my mind is at rest. 
Nevertheless I do not cease praying for you." 

On the same day (i3th March) on which 
Maria Celeste was thus hopefully writing, Niccolini 
had an audience of the Pope, in which he was 
informed that it would be necessary to summon 
Galileo to the Holy Office on the eve of the 
trial. It was the usage and could not be 
departed from. Again, the Ambassador pleaded 
the accused's bad health, great age, and the 
willingness he had shown to submit to any 
penalties ; but Urban replied it would not do to 
order otherwise. He regretted that Galileo "who 
had been his friend, with whom he had often 
held confidential intercourse, and eaten at the 
same table," should be subjected to these annoy- 
ances, but it was in the interests of religion. 

Notwithstanding this intimation, days and 
weeks passed, and yet Galileo w&s not summoned 
before the Inquisition. All this time, as we see 
from his letters, he was entertaining confident 
hopes of some favourable issue ; but, as a matter 
of fact, there were no grounds for this belief. 


Neither he nor his indefatigable friends, Castelli 
and Niccolini, could learn anything definite. The 
members of the Congregation, who alone could 
have given information, kept the secrets of the 
Holy Office very closely, as indeed they were 
bound to do under the severest penalties to 
themselves. Thus the month of March passed 
by ; April was come, and with it the storm 
which had been so long threatening. 

On the yth, Niccolini went to Cardinal 
Barberini by invitation, and was informed, on 
behalf of the Pope and the Congregation, that 
Galileo must appear before the Holy Office, and, 
as it was not known whether the case could be 
settled at a single sitting, it might be necessary 
to detain him. Once more the Ambassador urged 
consideration for his age and health (he had 
again been ill and confined- to bed), and begged 
the Cardinal to consider whether it would not be 
possible for him to return every evening to sleep 
at the Embassy. To these appeals his Eminence 
replied that such a permission was not to be 
expected. He promised, however, that every 
comfort would be afforded him in the buildings 
of the Holy Office ; that he would neither, as 
was customary with accused persons, be treated 
as a prisoner, nor be placed in a cell; but he 
would have good rooms, and, perhaps, his doors 
would not even be locked. Niccolini reported 
this notification to Cioli on pth April, adding the 
following interesting details : 

"This morning I also had a conversation with 


his Holiness, who again gave vent to his 
displeasure that Galileo should have discussed 
this subject which appears to him to be very 
serious, and of great moment to religion. Signor 
Galileo thinks, nevertheless, that, he can defend 
his statements on good grounds; but I have 
warned him to refrain from doing so, in order 
not to prolong the proceedings, and to submit 
to what shall be prescribed to him to believe 
respecting the motion of the earth. 1 He has 
fallen into the deepest dejection, and since 
yesterday has sunk so low that I am in great 
concern for his life. I shall beg that a servant 
may be allowed him, and as much comfort as 
the place will admit of. Meanwhile, we are all 
doing our best to console him and to help him 
through our recommendations to the most friendly 
disposed members of the Congregation; for truly 
he deserves every possible kindness that can be 
shown him. I cannot describe to you the grief 
of the whole house, for every one here loves him 

From this, then, we learn that up to 8th April 
Galileo was still intending to defend himself and 
his opinions, and that it was only on the earnest 
entreaty of the Ambassador that he gave up all 
idea of opposition, and resolved upon entire 

1 In a previous despatch of I9th February, he says : " I have 
advised Galileo to be always ready to obey and to submit to whatever 
was ordered, for this was the only way to allay the irritation of one 
who was so incensed, and who treated this affair as a personal one." 
Clearly, this "one" was no other than Urban VIII. 




ON 1 2th April 1633, Galileo appeared for his 
first examination before the Commissary- General 
of the Inquisition, Father Firenzuola, and the 
Procurator-Fiscal, Father Sincero. In all his 
answers he is actuated by one idea that of 
shortening the proceedings and averting severe 
measures by submissive acquiescence. According 
to the rules of the Holy Office, an oath is 
administered to the accused that he will speak 
the truth, and he is then asked whether he knows 
or conjectures the reason of his citation. Galileo 
replied that he supposed he had been summoned 
to give an account of his last book. After being 
asked if he acknowledged the work shown him, 
" Dialogo di Galileo Galilei, Linceo," as his, and 
his reply in the affirmative, the examiners led 
him back to his visit to Rome in 1616, and to 
what then happened in the matter of the pro- 
hibition. His answers show that he only knew 
of Cardinal Bellarmine*s admonition, as recorded 
in his certificate of 26th May 1616. That a 
"command" in more stringent terms was issued 


1632-1633] FIRST EXAMINATION 295 

to him (as the Inquisitor asserts) he is not 
aware, but, true to his resolve of submissiveness, 
he says again and again : " It may be so, but I 
do not remember it." He is then told that this 
" command " was to the effect that he must not 
hold, defend, or teach, in any way whatever, 
verbally or in writing, the doctrines of Copernicus. 
Galileo, who hears for the first time the exact 
terms of this further injunction "not to teach 
in any way whatever, verbally or in writing/' is 
amazed, but is still submissive. "It may be," 
he answers, ".that this injunction was also there, 
but I do not remember it." He then appeals 
again to Cardinal Bellarmine's certificate, " in 
which," he says, " there is no mention of this 
further injunction which has just been made 
known to me." 

After trying by every artifice to get from him 
an admission that this further injunction was laid 
upon him, and after his declaring for the fifth time 
that he did not remember any " command" beyond 
the admonition of Cardinal Bellarmine, the In- 
quisitor asked whether he had received any per- 
mission to print his Dialogues, and if in the 
negotiations he had mentioned the " command" 
aforesaid. He replied : "I did not say anything 
about it when I asked for the Imprimatur. I did 
not think it necessary to say anything, because I did 
not consider that in writing the book I was acting 
contrary to, far less disobeying, the command * not 
to hold or defend ' the aforesaid opinions. I have 
neither maintained nor defended the opinion that 
the earth moves and that the sun is stationary, but 


have demonstrated the opposite, and shown that 
the arguments of Copernicus are weak and incon- 
clusive/' With this answer the first sitting of 
this memorable trial closed. Silence on matters 
connected with the proceedings having been im- 
posed on oath, Galileo was led to his apartments in 
the private quarters of the Procurator- Fiscal, where 
he received kind and considerate treatment. Writing 
to Bocchineri on i6th April, he says : 

"Contrary to custom, three large and comfort- 
able rooms have been assigned to me, with permission 
to walk about in the spacious corridors. My health 
is good, for which, next to God, I have to thank the 
great care of the Ambassador and his wife, who have 
a watchful eye for all comforts far more than I 

A servant was allowed to remain with him, 
Niccolini was permitted to send in his meals, and no 
obstacle was opposed to his free correspondence 
with the kind Ambassador. 

In their treatment of Galileo personally (unprece- 
dented for its considerateness), throughout the whole 
of these proceedings, the Inquisition did homage 
to his genius. Since the establishment in 1215 of 
this dreadful tribunal, no prisoner had ever been 
treated with such leniency ; for princes, prelates, and 
noblemen, all had been consigned to the secret dun- 
geons from the very commencement of their trial. 
The Pope himself in an interview with Niccolini (re- 
ported in his despatch to Cioli, 27th February 1633) 
said, apropos of this point, that Galileo was treated 
as a privileged person, and reminded the Am- 
bassador that in the recent case of a gentleman of 


the princely house of Gonzaga far different measures 
had been taken, that he had been not only carried 
to Rome by officers of the Inquisition, but was kept 
closely imprisoned for a long time before judgment 
was pronounced. 

On 1 5th April, three days after the first examin- 
ation, three counsellors of the Holy Office, Oregius, 
Inchofer, and Pasqualigus, delivered their opinions 
on the case. Oregius declared that in the Dialogues 
the doctrine that the earth moves and that the sun 
is stationary is held and defended. Inchofer 
declared that Qalileo not only taught and defended 
that doctrine, but was himself suspiciously inclined 
to it, and even held it to this day. Pasqualigus was 
of opinion that by the publication of his Dialogues 
Galileo had infringed the order of 1616 in respect to 
teaching and defending, and it was very suspicious 
that he held the prohibited doctrine. 

On hearing of her father's imprisonment Maria 
Celeste wrote in deep distress, 2oth April : 

" I have just been informed by Signor Bocchineri 
of your being imprisoned in the Holy Office. At 
this, though on the one hand it grieves me much, 
feeling sure that you are anxious and uneasy and, 
perhaps, without bodily comfort, yet on the other 
hand, considering that it must have come to this 
before the business could be terminated, and con- 
sidering also the benignancy with which you have 
personally been treated, and (above all) the righteous- 
ness of your cause and your innocence in this parti- 
cular matter, I feel comforted, and hope for a 
prosperous ending with the help of Almighty God, 
to Whom I cry without ceasing, recommending you 
to His care, with the greatest love and confidence. 
Only be of good cheer. Do not give way to grief, 


for fear of the effect it would have on your health. 
Turn your thoughts to God, and put your trust in 
Him who like a loving Father never forsakes those 
who trust in Him unceasingly. 

"My dearest Lord and father, I have written 
instantly on learning this news of you, that you 
might know how I sympathise with you in your 
distress. Perhaps, when you know this it will not 
be quite so hard to bean I have mentioned the 
news to no creature in this house, choosing to make 
my joy and gladness common to all, but to keep my 
troubles to myself. Consequently, every one is 
looking forward joyfully to seeing you back again. 
And who knows ? Perhaps, even while I am writing 
the crisis may be passed, and you may be relieved 
of all anxiety. May it be the Lord's will, in whose 
keeping I leave you." 

Fearing that during Galileo's detention within 
the walls of the Holy Office, his letters to his 
daughter might be delayed if not detained, Caterina 
Niccolini (the Ambassador's wife) with sweet 
thoughtfulness wrote to Maria Celeste telling her 
what she knew of the situation, but still presenting 
the bright side (as Galileo himself had been doing) 
lest the poor nun should be too much distressed 
It would appear from more than one of Maria 
Celeste's letters that the father had spoken so 
much to the Ambassadress about his daughter as to 
make her Excellency wish for a personal acquaint- 
ance, and she signified her intention of paying the 
Sister a visit on her return to Florence. From a 
letter written to her father some time later, we learn 
that Maria Celeste was expecting Signora Caterina 
with a mixture of pleasure and trepidation. 

After the first hearing of his case on I2th April, 


weeks passed and no further open step was taken in 
the trial ; meanwhile, the prolonged deprivation of 
exercise in the open air which had been so essential 
to his health, combined with mental agitation, threw 
the old man on a sick bed. Writing on 23rd April 
to Geri Bocchineri he says : 

" I am writing in bed to which I have been con- 
fined for sixteen hours with severe pains in my 
loins, which according to my experience will last as 
much longer. A little while ago I had a visit from the 
Commissary and the Fiscal who conduct the enquiry. 
They have promised and intimated it as their settled 
intention to terminate the case as soon as I am able 
to get up again, encouraging me repeatedly to keep 
up my spirits. I place more confidence in these 
promises than in the hopes held out to me before, 
which as experience has shown were founded rather 
upon surmises than real knowledge. I have always 
hoped that my innocence and uprightness would be 
brought to light, and I now hope it more than ever. 

" Please send this on to my daughters and 
Vincenzio, as usual." 

The second examination was fixed for 28th 
April, and the course it now took had up to recent 
years puzzled all students of this famous trial 
While at the close of his first examination we 
have seen Galileo deny having defended the 
Copernican doctrine, and assert that he had done 
just the opposite, now at this second hearing and 
almost without waiting for the Inquisitor's questions, 
he makes a declaration which, roundabout though 
it is, contains a penitent confession that he had 
defended those doctrines. The cause of this 
change is explained by a letter from one of 


Galileo's judges, the Commissary - General 
Firenzuola (who was then with the Pope in the 
Castle of Gandolfo), to Cardinal Francesco 
Barberini, and dated 28th April. 1 This interest- 
ing letter (slightly condensed) runs as follows : 

"In compliance with the commands of his 
Holiness I yesterday informed the Congregation 
of the state of Galileo's case. Their Eminences 
approved of what has been done thus far, and took 
into consideration various difficulties with regard to 
the manner of pursuing the case, and of bringing it 
to an end. More especially as Galileo has in his 
examination denied what is plainly evident in his 
book; and in consequence of this denial there 
would result the necessity for greater rigour of 
procedure, and less regard to the other con- 
siderations belonging to the business. Finally, I 
suggested that the Congregation should grant me 
permission to treat extra-judicially with Galileo in 
order to render him sensible of his error, and bring 
him to a confession of the same ; and upon my 
indicating the grounds upon which I made the 
suggestion, permission was granted me. That no 
time might be lost I entered into discourse with 
Galileo yesterday afternoon, and, after many argu- 
ments and rejoinders had passed between us, by 
God's grace I attained my object, for I brought him 
to a full sense of his error, so that he is willing to 
confess it judicially. He requested, however, a 
little time in order to consider the form in which he 
might most fittingly make the confession. I trust his 
Holiness and your Eminence will be satisfied that 
in this way the affair will be settled without 
difficulty ; the Court will maintain its reputation ; 
it will be possible to deal leniently with the culprit ; 

1 First published in Heralisi's "Urbano VII I. e Galileo : Memorie 
Storiche," Rome, 1875, pp. 197-8. 


and, whatever the decision arrived at, he will 
recognise the favour shown him, with all the 
other consequences of satisfaction herein desired, 
To-day I think of examining him in order to obtain 
the said confession, and, having as I hope received 
it, it will only remain to me further to question him 
with regard to his intention, and to impose the 
prohibitions upon him ; and that done he might 
have the house [Niccolini's] assigned as a prison, as 
hinted to me by your Eminence." 

The second examination did not take place on 
28th April as Firenzuola proposed, perhaps on 
account of Galileo's indisposition. On 3Oth April 
the Court again assembled, the usual oath to speak 
the truth was administered, and Galileo was re- 
quested to state what he had to say. He then 
began the following melancholy confession : 

" In the course of some days' continuous and 
attentive reflection oft the interrogations put to me 
on the 1 2th of the present month, and in particular 
as to whether sixteen years ago an injunction was 
intimated to me by order of the Holy Office for- 
bidding me to hold, defend, or teach, in any manner, 
the opinion that had just been condemned of the 
motion of the earth and the stability of the sun it 
occurred to me to reperuse my printed Dialogues 
(which for three years I had not seen), in order 
carefully to note whethe^, contrary to my most 
sincere intention, there had by any inadvertence 
fallen from my pea anything from which a reader or 
the authorities might infer not only some taint of 
disobedience on my part, but also other particulars 
which might induce the belief that I had con- 
travened the orders of Holy Church. And being 
by the kind permission of th^ authorities at liberty 
to send about my servant, I sitffceeded in procuring 


a copy of my book, and having procured it I applied 
myself with the utmost diligence to its perusal and 
to a most minute consideration thereof. And, 
owing to my not having seen it for so long, it 
presented itself to me as if it were a new writing 
and by another author. I freely confess that in 
several places it seemed to me set forth in such a 
form that a reader ignorant of my real purpose 
might have had reason to suppose that the argu- 
ments adduced on the false side, and which it was 
my intention to refute, were so expressed as to be 
calculated rather to compel conviction by their 
cogency than to be easy of refutation. Two 
arguments there are in particular the one taken 
from the Sun-spots, the other from the ebb and 
flow of the tide which in truth come to the ear of 
the reader with far greater show of force and power 
than ought to have been imparted to them by one 
who regarded them as inconclusive and who in- 
tended to refute them ; as, indeed, I truly and 
sincerely held and do hold them to be inconclusive 
and admitting of refutation. And as excuse to 
myself for having fallen into an error so foreign to 
my intention, not contenting myself merely with 
saying that when a man recites the arguments of 
the opposite side with the object of refuting them, 
he should, especially if writing in the form of 
dialogue, state them in their strictest form, and 
should not cloak them to the disadvantage of his 
opponent. Not contenting myself with saying 
this, I now see I was misled by that natural com- 
placency which every man feels with regard to his 
own subtleties and in showing himself more skilful 
than the generality of men in devising, even in 
favour of false propositions, ingenious and plausible 
arguments. However, although with Cicero avidior 
sim gloriae quam satis est, if I had now to set 
forth the same reasonings, without doubt I should 


so weaken them that they should not be able 
to make an apparent show of force of which they 
are really and essentially devoid. My error then 
has been and I confess it one of vainglorious 
ambition and of pure ignorance and inadvertence. 
"This is what occurs to me to say with refer- 
ence to this particular, and what suggested itself 
to me during the reperusal of my book/' 

After making this humiliating declaration, 
Galileo was allowed to withdraw, and no questions 
were put to him ; but he must have concluded from 
this silence or other sign that he had not gone far 
enough in the denial of his inmost convictions ; 
perhaps, this penitent acknowledgment of error and 
vain-glory was not sufficient, and the Inquisitors 
would be conciliated by the resolution to publicly 
correct his error whatever prompted the impulse 
he returned at once to the Court and spoke as 
follows : 

" And in confirmation of my assertion, that I 
have not held and do not hold as true the opinion 
which has been condemned, if there shall be granted 
to me, as I desire, means and time to make a clearer 
demonstration thereof, I am ready to do so ; and 
there is a favourable opportunity for this, seeing 
that in the work the interlocutors agree to meet 
again after a certain time, to discuss several distinct 
problems of nature connected with the matter dis- 
cussed at their meetings. As this affords me an 
opportunity of adding one or two other 'days/ I 
promise to take up the arguments already adduced 
in favour of the said opinion, which is false and has 
been condemned, and to confute them in such most 
effectual manner as by the blessing of God will 
be possible to me. I pray, therefore, this sacred 


tribunal to aid me in this good resolution, and to 
enable me to put it into effect." 

On the evening of the day on which the second 
hearing took place, joth April 1633, Galileo was 
permitted to return to the Tuscan Embassy, on 
oath not to leave it, not to hold intercourse with 
any but the inmates of the house, to present him- 
self before the Holy Office when summoned, and to 
maintain the strktest silence on the subject of the 
trial. At this wholly unexpected favour, Niccolini 
and his household were, as we may imagine, filled 
with delight, and tvot less, we may be sure, was 
the rejoicittg* at San Matteo, when Galileo's letter 
arrived with th* goad news. Replying on ;th 
May, Mark Celeste *ly$ : 

" The kty that your last dear le&fer brought 
me, and ttte ttttiftg' to read k over and over to 
the nuhs, Who Jtiade fuite a jubilee on hearing 
its contents, ptft fne into such an excited state, 
that at last I girt a set etc headache. I do not 
say this to fepnsieh you, but to show how I take 
to heart all your dbnceras. And though I am not 
more strofcfly ^fefcted by What happens to you 
than a daufnter oigfht to be yet I dare to say that 
the love arid rfcteneftce I bft&r my dearest Lord 
and father 46 surpaifc by a bod deal that of the 
generality rf.ckugfetifrS; and I know that in like 
manner ne ejtcdt mdMk parent* in his love of me, 
his dattjjfhter, I ^N^ Ifcitty thffeks to our gracious 
God for thfe tffcfcieifcs ftfu ha^fc hitherto received. 
You justly &f mil ouf fhercies come fVom Him ; 
and though you considfet' these ftow received as 
an ansWfcf to !jf praytete, yet tmly they count 
for little df AOtMlf. But God knows how dearly 
I love yoc* tod ife He h*r me/' 


A week later, I4th May, she writes again: 

" You will have heard already what joy and 
comfort your last letter gave ITU*. As I was 
obliged to give it to Signor Geri that Vincenzio 
might see it, I made a copy which Signor Rondi- 
nelli will take into Florence to read to some of his 
friends, who he knew would be extremely glad to 
hear the particulars." 

After a long detailed account of her steward- 
ship in the management of his property, she 
goes on : 

" I wonder at Vincenzio never having written 
to you, and I glory in having been beforehand 
with him in writing constantly, notwithstanding 
that I too have sometimes found time wanting. 
To-day, I have written this at four different times, 
having had constant interruptions frtffa the phar- 
macy [of which she was kegper], atl& also from 
the toothache, which has been troublesome for 
many days past/' 

For once Maria Celeste sfcfcma to be unjust 
to her brother. Vincenzio did not write, it is 
true, but the reason was that fear of th6 plague 
had interrupted all communication between the 
healthy and the infected districts. He htd not 
long before condescended to accggt an appoint- 
ment as clerk at Poppi, chief town f the Cfcen- 
tino, a district to which the scotn|fe had not 
penetrated. Vincenzio does not apptar to fcfcve 
held this appointment very long, f we learn 
that, owing to his inefficiency and carelessness, he 
was requested to send in his resignation, or suffer 
dismissal. Writing to Galileo cm this subject, 
Bocchineri says : 


3 o6 THE INQUISITION [,632- 

" I wish you would write and tell him to mind 
his business, and not waste his time over his new 
invention a tuning-fork or some such thing 
which might serve well enough to employ him 
after business hours, but which ought not to be 
the principal occupation of the day/' 

Poor Galileo ! 

On loth May, Galileo was summoned for the 
third time before the Inquisition, where the Com- 
missary - General, Firenzuola, informed him that 
eight days were allowed in which to prepare a 
defence if he wished to do so; but Galileo at 
once handed in a paper, from which we may con- 
clude that it was written to order, and under the 
same extra-judicial pressure as made him write 
his humiliating confession of 3Oth April. The 
greater part of this document is taken up with 
an explanation why he had not mentioned the 
prohibition of 1616 when applying for the Im- 
primatur in 1630 which explanation amounts to 
a formal admission that on 26th February 1616 
he was not only commanded not to hold or 
defend the Copernican doctrine, but not to teach 
it in any way whatsoever. Coming then to the 
last paragraph he says : 

"Lastly, it remains for me to pray you to 
take into consideration my pitiable state of bodily 
indisposition, to which at the age of seventy years, 
I have been reduced by ten months of constant 
mental anxiety, and the fatigue of a long and 
toilsome journey at the most inclement season, 
together with the loss of the greater part of the 
years of which, from my previous condition of 
health, I had the prospect. I am encouraged to 


ask this indulgence by the clemency and good- 
ness of the most eminent lords, my judges, 
and hope that they will be pleased to remit what 
may appear good to their entire justice, and to 
consider my sufferings as adequate punishment" 

This touching appeal to the mercy of his judges 
cannot be read without feelings of the profoundest 
pity for the crushed old man, who in the evening 
of a glorious life was thus compelled to deny his 
inmost convictions, and to sue cravenly for that 
pity which was not to be shown him. 

After his paper had been received, and the 
same obligations imposed on him on oath as after 
the second hearing, he was allowed to return to 
the Embassy. The nearer the time approached 
when his illusions were to be dispelled, the more 
sanguine was the intelligence he sent to his 
friends. A favour granted just at the last, on 
the urgent solicitation of Niccolini, and unheard 
of in the annals of the Inquisition, might have 
encouraged these confident hopes. He was per- 
mitted to take the air in the gardens of the Villa 
Medici on the Pincio, to which, however, he was 
always conveyed in a closed carriage, as he must 
not be seen in the streets ! Niccolini did not share 
in these hopes of his guest After an audience 
of the Pope and Cardinal Barberini, he wrote 
to Cioli (22nd May) : 

" I very much fear that the book will be pro- 
hibited, unless it is averted by Galileo's being- 
charged (as I suggested) to write an apology. 
Some salutary penance will also be imposed, as 
they maintain that he has transgressed the com- 


mand given to him by Cardinal Bellarmine in 
1616. I have not yet told Galileo all this, 
because I want to prepare him for it by degrees, 
in order not to distress him." 

A lull now took place in the proceedings 
the preparation for the great catastrophe that 
was to crush Galileo and fill the educated world 
with horror. Sultry silence reigned for four 
weeks, and no one, not even Niccolini, could 
learn anything. Indeed, the thunderbolt had 
fallen before the fact was known outside the 
Holy Office. Galileo's fate had been sealed at 
a private meeting of the Congregation, i6th June 
1633, at which the Pope presided. It was 
decreed to try Galileo as to his intention, under 
threat of torture, and if this failed he was then 
to be called upon to recant before a plenary 
assembly of the Holy Office; to be condemned 
to imprisonment at their pleasure; and to be 
ordered in future not to discuss in writing or 
speaking the opinion that the earth moves and 
that the sun is stationary, nor even the contrary 
opinion, under pain of further punishment as a 
relapsed heretic. Further, the work "Dialogo di 
Galileo Galilei, Linceo," was to be prohibited. 1 
And, in order to make this known everywhere, 
copiesv of the sentence were to be sent to all 
Papal envoys and to all Inquisitors into heretical 
crimes, and especially to the Inquisitor in Florence, 
who were to read it publicly to all professors of 
mathematics summoned for the purpose. 

1 From the Vatican MSS. it was apparently first intended to 
publicly burn the book, but after the decree was drafted, the words 
Cremandum fere were erased and prohibendum fore inserted. 


Two days after these proceedings had been 
determined on, the Pope received Niccolini, who 
once more came to beg for a speedy termination 
of the trial, the long suspense of which was 
torturing to him only in a less degree than it 
was to Galileo himself. Urban coolly replied 
that it had already been terminated, and that 
within the next few days Galileo would be 
summoned to hear his sentence. The Ambas- 
sador, aghast at this unexpected answer, implored 
the Pope to mollify any severity that the judges 
might, perhaps, have" thought necessary, and added 
that the great complaisance hitherto shown to 
his Sovereign's wishes in the matter was fully 
appreciated, and that the Grand Duke was only 
waiting the end of the business to express his 
gratitude in person. The Pope replied that his 
Highness need not take this trouble, that he had 
readily granted every amelioration possible; but 
as to Galileo's opinions they could do no less than 
prohibit them as erroneous and contrary to 
Holy Scripture, and as to his person, he would, 
according to usage, fee imprisoned for a time, 
because he had transgressed the mandate issued 
to him in 1616. " However," added Urban, 
"after the publication of the sentence we will 
see you again and we will consult together so 
that he may suffer as little distress as possible." 

The same day, i8th June, Niccolini reported 
this audience to Cioli, and remarked at the end 
that he had simply informed Galileo of the 
approaching end of the trial and of the prohibi- 
tion of his book, but had said nothing about the 


personal punishment, in order not to trouble him 
too much at once. The Pope had also enjoined 
this course, " because, perhaps, in the course of 
the proceedings things might take a better turn/' 
The drama now rapidly proceeded to a climax. 
On the evening of 2Oth June 1633, Galileo was 
warned to appear before the Inquisition on the 
following morning, when, as we know from the 
programme of i6th June, he was to be questioned 
under threats of torture about his "intention" 
that is, as to his real convictions. 

On the morning of the 2ist, Galileo appeared 
before his judges. After he had taken the usual 
oath and had answered in the negative the query 
whether he had any statement to make, the 
examiner asked three separate questions, slightly 
varied but all to the effect whether he has held 
and holds the opinion that the sun is the centre 
of the world, and that the earth is not the 
centre, but moves, and with a diurnal motion. 
To these Galileo suitably replied in the negative. 
" I do not hold," he says, in reply to the last 
query, " and have not held this opinion of 
Copernicus since the command was given me 
that I must abandon it. For the rest I am here 
in your hands, do with me as you please. J1 
Being once more bidden to speak the truth, 
otherwise recourse would be had to torture, the 
terrified old man answered with the resignation 
of despair, "I am here to obey. I have not 
held this opinion since the decision was pro- 
nounced, as I have stated." 

In the protocol of the trial the concluding 


sentence follows immediately after Galileo's answer, 
"And as nothing further could then be done 
in execution of the decree [of i6th June] his 
signature was obtained to his depositions, and he 
was sent back to his place," that is, to some 
place in the buildings of the Holy Office, where 
he was detained till 24th June. 1 

We have no information as to the treatment 
he received this time. Was he put into the 
apartments he had occupied before, or was he 
confined in a prisoner's cell? From the con- 
siderate treatment in outward things which 
Galileo met with during his trial, we may, 
perhaps, conclude that he was not thrown into 
the dungeons of the Inquisition as so many 
historians are fond of repeating. Neither is 
there, as we shall presently see, the slightest 
foundation for another vulgar error that he was 
actually put to the torture. 

3 Despatch, Niccolini to Cioli, 26th June 1633. 




ON Wednesday, 22nd June 1633, in the forenoon, 
Galileo was conducted to the large hall used 
for melancholy proceedings of this kind in 
the Dominican Convent of Santa Maria sopra 
Minerva, where in the presence of his judges 
and a large assemblage of cardinals and prelates 
of the Church his sentence was read to him as 
follows r 1 

" We, the undersigned, 

Gasparo of Santa Croce in Gerusalemme, Borgia, 

Fra Felice Centino of S. Anastasia, called Ascoli, 

Guido of Santa Maria del Popolo, Bentivoglio, 

Fra Desiderio Scaglia of S. Carlo, called Cremona, 

Fra Antonio Barberini, called S. Onofrio, 3 

Laudivio Zacchia of S. Pietro in Vincoli, called San-Sisto, 

Berlingero of San Agostino, Gessi, 

Fabrizio of S. Lorenzo in Pane e Perna, Verospi, 

Francesco of S. Lorenzo in Damaso, Barberini, 8 

Martino of Santa Maria Nuova, Ginetti, 

"by the grace of God, Cardinals of the Holy 

1 Jean-Jacques Bouchard writing from Rome to Micanzio, 29th 
June 1633, says " he was conducted as a criminal in penitential garb." 

2 Pope's brother. 3 p ope > s ne phew. 

1633] SENTENCE 313 

Roman Church, Inquisitors General throughout 
the whole Christian Republic, Special Deputies 
of the Holy Apostolical Chair against heretical 
depravity : 

" Whereas you, Galileo, son of the late 
Vincenzio Galilei, of Florence, aged 70 years, 
were denounced, in 1615, to this Holy Office, 
for holding as true a false doctrine taught by 
many, namely, that the sun is immovable in the 
centre of the world, and that the earth moves, 
and also with a diurnal motion ; also, for having 
pupils whom you instructed in the same opinions ; 
also, for maintaining a correspondence on the 
same with some German mathematicians ; also 
for publishing certain letters on the sun-spots, in 
which you developed the same doctrine as true ; 
also for answering the objections which were 
continually produced from the Holy Scriptures, 
by glozing the said Scriptures according to your 
own meaning; and whereas thereupon was pro- 
duced the copy of a writing, in form of a letter, 
professedly written by you to a person formerly 
your pupil, in which, following the hypothesis of 
Copernicus, you include several propositions 
contrary to the true sense and authority of the 
Holy Scriptures ; therefore (this Holy Tribunal 
being desirous of providing against the disorder 
and mischief which were thence proceeding and 
increasing to the detriment of the Holy Faith) 
by the desire of his Holiness and of the Most 
Eminent Lords, Cardinals of this supreme and 
universal Inquisition, the two propositions of the 
stability of the sun, and the motion of the earth, 
were qualified by the Theological Qualifiers as 
follows ; 

" i. The proposition that the sun is in the 
centre of the world and immovable from its 
place is absurd, philosophically false, and formally 


heretical ; because it is expressly contrary to 
the Holy Scriptures. 

"2. The proposition that the earth is not 
the centre of the world, nor immovable, but that 
it moves, and also with a diurnal motion, is also 
absurd, philosophically false, and, theologically 
considered, at least erroneous in faith. 

" But whereas, being pleased at that time to 
deal mildly with you, it was decreed in the Holy 
Congregation, held before his Holiness on the 
twenty -fifth day of February 1616, that his 
Eminence the Lord Cardinal Bellarmine- should 
enjoin you to give up altogether the said false 
doctrine ; and if you should refuse, that you should 
be ordered by the Commissary of the Holy Office 
to relinquish it, not to teach it to others, nor 
to defend it ; and in default of acquiescence, 
that you should be imprisoned ; and whereas in 
execution of this decree, on the following day, 
at the Palace, in presence of his Eminence the 
said Lord Cardinal Bellarmine, after you had been 
mildly admonished by the said Lord Cardinal, 
you were commanded by the Commissary of the 
Holy Office, before a notary and witnesses, to 
relinquish altogether the said false opinion, 
and, in future, neither to defend nor teach it in 
any manner, neither verbally nor in writing, 
and upon your promising obedience you were 

" And, in order that so pernicious a doctrine 
might be altogether rooted out, nor insinuate 
itself further to the heavy detriment of the 
Catholic truth, a decree emanated from the Holy 
Congregation of the Index prohibiting the books 
which treat of this doctrine, declaring it false, 
and altogether contrary to the Holy and Divine 

"And whereas a book has since appeared 

1633] SENTENCE 315 

published at Florence last year, the title of which 
showed that you were the author, which title is 
'The Dialogue of Galileo Galilei, on the two 
principal Systems of the World the Ptolemaic 
and Copernican ' ; and whereas the Holy Con- 
gregation has heard that, in consequence of 
printing the said book, the false opinion of the 
earth's motion and stability of the sun is daily 
gaining ground, the said book has been taken 
into careful consideration, and in it has been 
detected a glaring violation of the said order, 
which had been intimated to you ; inasmuch as 
in this book you have defended the said opinion, 
already, and in your presence, condemned ; 
although, in the same book, you labour with 
many circumlocutions to induce the belief that 
it is left by you undecided and merely probable ; 
which is equally a very grave error, since an 
opinion can in no way be probable which has 
been already declared and finally determined 
contrary jo the Divine Scripture. Therefore, by 
Our order, you have been cited to this Holy 
Office, where, on your examination upon oath, 
you have acknowledged the said book as written 
and printed by you. You also confessed that you 
began to write the said book ten or twelve 
years ago, after the order aforesaid had been 
given. Also, that you had demanded licence to 
publish it, without signifying to those who granted 
you this permission that you had been commanded 
not to hold, defend, or teach, the said doctrine 
in any manner. You also confessed that the 
style of thfc said book was, in many places, so 
composed that the reader might think the argu- 
ments adduced on the false side to be so 
worded as more effectually to compel ^conviction 
than to be easily refutable, alleging, in excuse, 
that you had thus run into an error, foreign 


(as you say) to your intention, from writing in 
the form of a dialogue, and in consequence of 
the natural complacency which every one feels 
with regard to his own subtleties, and in showing 
himself more skilful than the generality of mankind 
in contriving, even in favour of false propositions, 
ingenious and plausible arguments. 

" And, upon a convenient time being given 
you for making your defence, you produced a 
certificate in the handwriting of his Eminence 
the Lord Cardinal Bellarmine, procured, as you 
said, by yourself, that you might defend yourself 
against the calumnies of your enemies, who 
reported that you had abjured your opinions, 
and had been punished by the Holy Office ; in 
which certificate it is declared that you had not 
abjured nor had been punished, but merely that 
the declaration made by his Holiness, and pro- 
mulgated by the Holy Congregation of the Index, 
had been announced to you, which declares that 
the opinion of the motion of the earth and stability 
of the sun is contrary to the Holy Scriptures, 
and, therefore, cannot be held or defended. Where- 
fore, since no mention is there made of two articles 
of the order, to wit, the order ' not to teach ' and 
*in any manner/ you argued that we ought to 
believe that, in the lapse of fourteen or sixteen 
years, they had escaped your memory, and that 
this was also the reason why you were silent as 
to the order when you sought permission to 
publish your book, and that this is said by you, 
not to excuse your error, but that it may be 
attributed to vain-glorious ambition rather than 
to malice. But this very certificate, produced 
on your behalf, has greatly aggravated your 
offence, since it is therein declared that the said 
opinion is contrary to the Holy Scriptures, and 
yet you have dared to treat of it, and to argue 

1633] SENTENCE 317 

that it is probable. Nor is there Vmy extenuation 
in the licence artfully and cunningly extorted by 
you, since you did not intimate the command 
imposed upon you. But whereas it appeared to 
Us that you had not disclosed the whole truth 
with regard to your intention, We thought it 
necessary to proceed to the rigorous examination 
of you, in which (without any prejudice to what 
you had confessed, and which is above detailed 
against you, with regard to your said intention) 
you answered like a good Catholic. 1 

"Therefore, having seen and maturely con- 
sidered the merits of your cause, with your said 
confessions and excuses, and everything else which 
ought to be seen and considered, We have come 
to the underwritten final sentence against you : 

" Invoking, therefore, the most holy name of 
our Lord Jesus Christ, and of His Most Glorious 
Virgin Mother, Mary, We pronounce this Our 
final sentence, which, sitting in council and 
judgment with the Reverend Masters of Sacred 
Theology and Doctors of both Laws, Our Assessors, 
We put forth in this writing in regard to the 
matters and controversies between the Magnificent 
Carlo Sincero, Doctor of both Laws, Fiscal Proctor 
of the Holy Office, of the one part, and you, 
Galileo Galilei, defendant, tried and confessed 
as above, of the other part, We pronounce, judge, 
and declare, that you, the said Galileo, by reason of 
these things which have been detailed in the course 
of this writing, and which, as above, you have 
confessed, have rendered yourself vehemently 
suspected by this Holy Office of heresy, that is of 
having believed and held the doctrine (which is 
false and contrary to the Holy and Divine 

1 The phrase is vague and purposely so, for clearly, even the 
, threat of torture could not extort from Galileo the wished-for avowal 
of his "intention," that is of his still holding- the condemned opinion. 
See Martin's "GalileV PP- 129-31. 


Scriptures), that the sun is the centre of the world, 
and that it does not move from east to west, and that 
the earth does move, and is not the centre of the 
world ; also, that an opinion can be held and 
supported as probable, after it has been declared 
and finally decreed contrary to the Holy Scripture, 
and, consequently, that you have incurred all the 
censures and penalties enjoined and promulgated in 
the sacred canons and other general and particular 
constitutions against delinquents of this description. 
From which it is Our pleasure that you be absolved, 
provided that with a sincere heart and unfeigned 
faith, in Our presence, you abjure, curse, and 
detest, the said errors and heresies, and every 
other error and heresy, contrary to the Catholic 
and Apostolic Church of Rome, in the form now 
shown to you. 

" But that your grievous and pernicious error 
and transgression may not go altogether un- 
punished, and that you may be made more cautious 
in future, and may be a warning to others to 
abstain from delinquencies of this sort, We decree 
that the book ' Dialogues of Galileo Galilei ' be 
prohibited by a public edict, and We condemn 
you to the formal prison of this Holy Office for 
a period determinable at Our pleasure ; and by 
way of salutary penance, We order you during the 
next three years to recite, once a week, the seven 
penitential psalms, reserving to Ourselves the 
power of moderating, commuting, or taking off, 
the whole or part of the said punishment or 
penance. 1 

1 Accordingly, the work was placed on the Index Expurgatorius, 
and for more than a hundred years after, it was not allowed to be 
printed in Italy, and then (1744) the editot had to state expressly in 
an introduction that the theory of the double motion of the earth must 
be regarded only as a mathematical hypothesis to facilitate the ex- 
planation of certain natural phenomena. He had also to prefix the 
sentence of the Holy Office and Galileo's recantation, as well as 

i6 3 3] ABJURATION 319 

"And so We say, pronounce, and by Our 
sentence declare, decree, and reserve, in this and in 
every other better form and manner, which lawfully 
We may and can use. So We, the subscribing 
Cardinals, pronounce. 

' FELIX, Cardinal di Ascoli. 
'GuiDO, Cardinal Bentivoglio. 
c DESIDERIO, Cardinal di Cremona. 
{ ANTONIO, Cardinal S. Onofrio. 
BERLINGERO, Cardinal Gessi. 
6 FABRIZIO, Cardinal Verospi. 
* MARTINO, Cardinal Ginetti." 

In conformity with the foregoing sentence, 
Galileo was made to kneel before the Inquisition, 
and make the following abjuration : 

" I, Galileo Galilei, son of the late Vincenzio 
Galilei of Florence, aged seventy years, being 
brought personally to judgment, and kneeling 
before you, Most Eminent and Most Reverend 
Lords Cardinals, General Inquisitors of the 
Universal Christian Republic against heretical 
depravity, having before my eyes the Holy Gospels 
which I touch with my own hands, swear that I 
have always believed, and, with the help of God, 
will in future believe, every article which the Holy 
Catholic and Apostolic Church of Rome holds, 
teaches, and preaches. But because I have been 

Calmet's essay "On the System of the Universe of the Ancient 
Hebrews," in which the passages of Scripture relating to the order of 
the world are supposed to be interpreted in true Catholic fashion. 
But see p. 427 infra. 

After many attempts in the next eighty years to have the decree of 
5th March 1616 (prohibiting all books which teach the Copernican 
doctrine) expunged, it was finally resolved, nth September 1822, 
" that the printing and publication of works treating of the motion of 
the earth and the stability of the sun, in accordance with the opinion 
of modern astronomers, is permitted in Rome." Accordingly, in the 
next edition of the Index, published in 1835, Galileo's name, Kepler's, 
and those mentioned in the decree of 5th March 1616, were expunged. 


enjoined, by this Holy Office, altogether to abandon 
the false opinion which maintains that the sun is 
the centre and immovable, and forbidden to hold, 
defend, or teach, the said false doctrine in any 
manner ; and because, after it had been signified to 
me that the said doctrine is repugnant to the Holy 
Scripture, I have written and printed a book, in 
which I treat of the same condemned doctrine, and 
adduce reasons with great force in support of the 
same, without giving any solution, and therefor have 
been judged grievously suspected of heresy ; that is 
to say, that I held and believed that the sun is the 
centre of the world and immovable, and that the 
earth is not the centre and movable, I am willing 
to remove from the minds of your Eminences, 
and of every Catholic Christian, this vehement 
suspicion rightly entertained towards me, therefore, 
with a sincere heart and unfeigned faith, I abjure, 
curse, and detest the said errors and heresies, and 
generally every other error and sect contrary to the 
said Holy Church ; and I swear that I will never 
more in future say, or assert anything, verbally or 
in writing, which may give rise to a similar sus- 
picion of me ; but that if I shall know any heretic, 
or any one suspected of heresy, I will denounce 
him to this Holy Office, or to the Inquisitor and 
Ordinary of the place in which I may be. I swear, 
moreover, and promise that I will fulfil and observe 
fully all the penances which have been or shall be 
laid on me by this Holy Office. But if it shall 
happen that I violate any of my said promises, 
oaths, and protestations (which God avert ! ), I 
subject myself to all the pains and punishments 
which have been decreed and promulgated by the 
sacred canons and other general and particular 
constitutions against delinquents of this description. 
So, may God help me, and His Holy Gospels, 
which I touch with my own hands, I, the above 

i6 3 3] DID THE JUDGES AGREE? 321 

named Galileo Galilei, have abjured, sworn, 
promised, and bound myself as above ; and, in 
witness thereof, with my own hand have subscribed 
this present writing of my abjuration, which I have 
recited word for word. 

"At Rome, in the Convent of Minerva, 22nd 
June 1633, I Galileo Galilei, have abjured as above 
with my own hand." l 

A notable circumstance connected with these 
papers is that, whereas the names of ten Cardinals 
appear in the preamble of the sentence, only seven 
subscribed it The three who did not sign deserve 
to be specifically mentioned ; they were Gasparo 
Borgia, Laudivio Zacchia, and Francesco Barberini, 
the Pope's nephew. Why did these Cardinals 
abstain from signing ? Were they absent accident- 
ally, or on purpose ? Or did they dissent and refuse 
to sign ? We shall probably never know ; but 
bearing in mind the many instances of Francesco 
Barberini's good offices in Galileo's behalf, we shall 
not be far wrong, I think, if we conclude that they 
did not sign because they did not approve the sen- 
tence. Another of the ten, Cardinal Bentivoglio, 

1 The Vatican MSS. relating to Galileo's trial have a curious 
history of their own. They were carried away in 1809 by order of 
Napoleon to Paris, where they remained until his first abdication. 
Just before the Hundred Days, the King, Louis XVI 1 1., wishing to 
inspect them, ordered them to be sent to his private apartments. In 
the hasty flight which soon afterwards followed, the MSS. were 
forgotten, and disappeared in an unaccountable way. After some 
years they were restored to Pope Gregory XVI., in an equally 
mysterious manner, and were finally replaced in the Vatican Library 
by Pope Pius IX,, in 1848. A French translation, begun by 
Napoleon's orders, was brought down to 3oth April 1633, when, no 
doubt, the Emperor's abdication prevented its completion. For more 
on this subject, see Favaro's "Document! del Processo di Galileo," 
Venice, 1902. 



although he signed, is said to have done his 
best to prevent the decision arrived at ; which 
is likely enough, seeing that he studied under 
Galileo in Padua, and was always reckoned as 
one of his disciples, 1 We may, then, suppose 
that at least four of the ten judges were against 
the sentence, which, if true, is another indica- 
tion of the determination of Urban VIII. to 
punish his quondam friend for calling him a 
simpleton. 2 

It is also noteworthy that not one of the decrees 
or orders relating to this trial is ratified by the 
Pope. They all begin with the words Sanctissimus 
mandavit, but bear no Papal signature. This is 
equally the case in the proceedings of 1616 as in 
those of 1633. This fact is made much of by 
apologists of the Church of Rome. They argue 
that from the absence of the Pope's signature the 
Church cannot be held responsible. Galileo, they 

1 See his " Memorie," Venice, 1648, p. 123 ; also p. 288 ante, where 
Galileo says that Cardinals Bentivoglio and Scaglia were well 
disposed towards him. The Pope told Niccolini on i8th June that 
the Cardinals were unanimous " in intending to impose a penance." 
But were they unanimous in all other matters ? It is well to note (as 
Professor Favaro points out) that his Holiness was not always sincere 
in his communications to Niccolini, 

2 Since the above was written, I^have received a letter from Pro- 
fessor Favaro in which he says : "The omission of the signatures has 
not the significance hitherto ascribed to it. The three Cardinals were 
not present, but there can be little doubt that, notwithstanding their 
good disposition towards Galileo personally (a feeling which was 
shared by others on the bench), they were assenting parties. Cardinal 
Borgia was at the time Spanish Ambassador to Rome, his relations 
with the Pope and the Barberini faction were strained, and he seldom 
if ever attended the sittings of the Holy Office. Cardinal Barberini, 
as we learn from one of Niccolini's despatches, never attended the 
Wednesday sittings. Cardinal Zacchia's absence was probably acci- 
dental, perhaps on account of ill-health." 


say, was persecuted, not by the Pope, Urban VIII., 
the infallible vicar of Christ, but by the man, Maffeo 
Barberini, and his tools the Cardinals. Granted : 
but suppose a man be persecuted by the police in 
the name of, and to the knowledge of, the higher 
powers, are these higher powers to get off scot-free, 
because they did not put their hand and seal to the 
documents authorising the acts of their subordinates ? 
However, since the apologists admit the persecution, 
we leave them to derive what comfort they can from 
their casuistical argument. 1 

For a long time it was a popular error that 
Galileo was subjected to torture. 2 The assertion is 
based on the mention in the sentence of a rigorous 
examination under which Galileo answered as 
became a good Catholic ; and in support it is 
pointed out that after this time he was afflicted 
(in addition to his other maladies) with hernia, which 
was said-to be the usual consequence of "torture by 
the cord." Now, as regards the latter it is enough 
to say that hernia was an old complaint, and is 
certified to by the Florentine physicians in their 
certificate of i7th December 1632, already quoted 
in these pages. As regards the rigorous exa- 
mination, all histories of the Inquisition show that 
this formula consisted of five stages which had to 
be strictly followed : (i) threat in Court that extreme 
measures would be resorted to ; (2) taking the 

1 For an excellent review^showing the injustice and illegality of 
these proceedings, see Von Getter's " Galileo and the Roman Curia," 
pp. 234-42, or Martin's " Galile'e,' chap, vii., where the whole affair is 
exhaustively discussed from a different standpoint. 

2 The fable is not dead yet, even amongst educated people. The 
latest repetition of it occurs in an article in the Fortnightly Review 
for .March 1902. 


accused into the torture chamber, renewing the 
threat, and showing him the instruments of torture ; 
(3) undressing and binding ; (4) laying him on the 
rack; and (5) actual torture (territio realis\ Now, 
a close study of the proceedings clearly shows that 
it was not necessary to go beyond the first stage, for 
the compliance of the accused saved his judges 
from the ineffable disgrace of the crowning infamy. 
The difference to a man of Galileo's genius, years, 
and infirmities, was little if anything. The whole 
period of the trial, from his first citation to Rome on 
ist October 1632 to the closing scene on 22nd 
June 1633, was one continued infliction of moral 
torture. The repeated denials of his inmost con- 
victions, and the final abjuration on bended knees, 
must have wrung his soul as severely as physical 
torture could have wrung the muscles and tendons 
of his body. 

Another error which early biographers were fond 
of repeating, but of which a moment's reflection 
would have shown the absurdity, was that Galileo 
on rising from his knees after reciting the abjur- 
ation muttered Eppur si muove (it moves, never- 
theless). Some writers, doubtless to make the 
story more vraisemblable, provide a friend to 
whom the words are whispered. But consider for 
a moment the situation : an old man of seventy 
years, suffering in body, and distressed in mind by 
the accumulated anguish of a ten months' trial, 
alone and without support in the midst of that stern 
assembly of Inquisitors. Is it likely that at such a 
moment he would have muttered or uttered these 
words? He must have known that the slightest 

1633] EPPUR SI MUOVE 325 

indication by words or gesture of such a state of 
mind would have consigned him for life to the 
deepest dungeons of the Inquisition, if to no 

worse. 1 

While the older writers go to one extreme and 
say that Galileo was tortured, thrown into a dungeon 
for years, or for the rest of his life, was in physical 
fact a martyr, some recent ones go to the other ex- 
treme, and say he had no claim to much sympathy, 
brought his troubles on himself by want of tact and 
temper, was, in fact, as little of a martyr as it was 
possible to be. Others, again, blame him for not 
" seeing this thing through." Brewster, for example, 
compares him to the Christian martyr, and finds him 
sadly degenerate. " Had Galileo," he says, "but 
added the courage of the martyr to the wisdom of 
the sage ; had he carried the glance of his indignant 
eye round the circle of his judges ; had he lifted his 
hands to Heaven, and called on the living God to 
witness the truth and immutability of his opinions, 
the bigotry of his enemies would have been dis- 
armed, and science would have enjoyed a memorable 
triumph." Perhaps ; but perhaps on the other hand, 
his judges, instead of being cowed by the glance of 
his eye, would have delivered him to the stake, as 
they did Giordano Bruno earlier in the century 
(1600), and Marc' Antonio de Dominis only eight 
years before. 2 Revealed truth may require its 
martyrs, at least so Tertullian tells us the blood 

1 The earliest mention of "Eppur si muove" occurs in "Querelles 
Litt&raires," by L'Abbe* Irailh, Paris, 1761, vol. iii. p. 49. 

3 De Dominis died in prison (1624) in the course of his trial, but 
his body was burned with his books by sentence of the Inquisition 
pour encourager les autres^ I suppose. 


of the martyrs is the seed of the Church; but 
scientific truth certainly requires none,/W Brewster, 
for, as the Koran (strange authority) teaches, "the 
ink of the scholar and the blood of the martyr are 
of equal value in the eye of Heaven. " Much as 
Galileo did for science, he would probably have 
done more were his life less stormy. From his 
entry into public life in 1589 to his death in 1642, 
he was seldom free from polemics. For over fifty 
years he was the knight militant of science, and 
almost alone did successful battle with the hosts of 
Churchmen and Aristotelians who attacked him on 
all sides one man against a world of bigotry and 
ignorance. If, then, once and only once, when face 
to face with the terrors of the Inquisition, he, like 
Peter, denied his Master, no honest man, knowing 
all the circumstances, will be in a hurry to blame 

After this sorrowful drama had been concluded, 
Galileo was led back to the buildings of the Holy 
Office. And now that he and the Copernican 
system had been condemned with all the terrify- 
ing forms of the Inquisition, Urban 's wounded 
vanity was soothed, and he was pleased to give 
the word for a little mercy. Galileo was not, as 
the sentence prescribed, to be detained in the prison 
of the Holy Office, but was banished to the villa 
of the Grand Duke of Tuscany at Trinita dei 
Monti, which, by Papal orders dated 23rd June, 
he was to consider as a prison. Thither, where, 
many years before, he had shown the moons of 
Jupiter and other " Celestial Novelties" to wonder- 
ing cardinals, he was now conducted by the 


ever-faithful Niccolini on the evening of 24th 

From Niccolini J s letter to Cioli of 26th June 
we learn that while Galileo took the prohibition 
of his book (for which his friend had prepared 
him) with tolerable composure, the wholly un- 
expected proceedings against himself personally 
affected him terribly. He sank into a deep de- 
pression from which the Ambassador did his best 
to rouse him, but with little success for a time. 

In accordance with the decree of i6th June 
1633, copies of the sentence and abjuration were 
despatched to all Papal Nuncios, all Inquisitors, 
and many Universities, Italian and Foreign. In 
Padua and Florence especially, the means of publi- 
cation were calculated with a refinement of cruelty. 
In Padua the local Inquisitor read both documents 
to the professors of philosophy and mathematics, 
and to the students convened for the purpose in 
the University library. A search was made for 
copies of the condemned book, and if none were 
found the Inquisitor could at least boast of one 
voluntary surrender. The peripatetic Fortunio 
Liceti gave up his copy a presentation one by 
the author! In Florence the Inquisitor read the 
sentence and abjuration publicly in the church 
of Santa Croce, notices to attend having been 
previously served on all professors, and on all 
others who were known to be friends and ad- 
herents of Galileo. Thus Aggiunti, Guiducci, 
Arrighetti, and many others who loved the great 
master were made to participate in his humiliation. 1 

1 See Guiducci's letter to Galileo, dated 27th August 1633, 


But the cup of Papal wrath was not emptied 
on Galileo's head alone. All who had befriended 
him, or had any part in the licensing of his 
Dialogues, were punished in some way. Ciampoli, 
in December 1632, was deprived of his office of 
Secretary of the Papal Briefs and was (practically) 
exiled as Governor of Montalto, where he remained 
as long as he lived Galileo's faithful disciple to 
the last Early in April 1633 Galileo was deprived 
of the valuable advocacy of the devoted Castelli, 
who was sent away on some pretext, and was not 
recalled until the middle of 1635, when "At last 
he had again been permitted to kiss his Holiness's 
toe. JJ The Inquisitor in Florence was severely repri- 
manded, and Riccardi, the Censor, was dismissed in 
disgrace and deprived of all offices during Urban's 

The inconsistency of these proceedings will 
be noted in the latter cases. These people are 
punished for granting that very licence which 
Galileo was charged with, and condemned for, 
having surreptitiously obtained from them by con- 
cealing circumstances with which they were not 
bound to be acquainted. Riccardi, in exculpation 
of his conduct, produced a letter from Ciampoli, 
in which it was said that his Holiness (in whose 
presence the letter professed to be written) ordered 
the licence to be given ; but the Pope only replied 
that this was a Ciampolism ; that his Secretary and 
Galileo had circumvented him ; that he had already 
dismissed Ciampoli, and that Riccardi must prepare 
to follow him. 

On the news of Galileo's condemnation reaching 


his daughter, Maria Celeste wrote (on 2nd 
July) :_ 

"The news of your fresh trouble has pierced 
my soul with grief all the more that it came upon 
me quite unexpectedly. Not having had a letter 
from you this week, I feared something must have 
happened, and importuned Signor Geri to tell me. 
What I hear from him of the resolution they have 
taken concerning you and your book gives me 
extremest pain, not having expected such a result. 
Dearest Lord and father, now is the time for the 
exercise of that wisdom with which God has en- 
dowed you. Thus, you will bear these blows with 
that fortitude of soul which religion, your age, and 
your profession, alike demand." 

Receiving no news direct from Galileo for some 
days after the promulgation of the sentence in 
Florence, Geri Bocchineri and Niccol6 Aggiunti, 
fearing a descent on the villa at Arcetri by the 
familiars of the Inquisition, requested the keys of 
the house from Maria Celeste that they might do 
what Galileo had told them might be necessary 
to his safety should certain contingencies arise. 
Writing on I3th July, she tells her father: 

"They feared you were in trouble, and seeing 
how exceedingly anxious they were oil your account, 
it seemed to me right and n'ecessary to prevent any 
accident, therefore I gave them the keys and per- 
mission to do as they thought fit" 

The author of the " Private Life of Galileo" 
thinks the work here hinted at was the burning of 
such writings in Galileo's library as might be used 
to further incriminate him. 

330 EXILED TO SIENA [1633 

"It is probable," the author says, "that much 
which was precious was destroyed on this occasion ; 
and this may fully account for the disappearance 
of those incompleted writings of which mention 
is made in his correspondence, but of which no 
trace remains " (p. 263). 

It is highly probable that as a matter of pre- 
caution Galileo's friends took away for safe hiding 
certain of his papers ; but that anything was actually 
destroyed I doubt. With the exception of those 
early treatises (some of which may never have 
been written), noted on p. 120, no important paper 
of his is missing, and there is no perceptible break 
in his correspondence, except that already noted 
for the year of his third visit to Rome in I6I6. 1 

Galileo, after his first great anguish had some- 
what subsided, felt that he must quit Rome and 
its hateful memories, and so addressed a pitiable 
letter to the Pope. 

" Most Holy Father," he says, " Galileo Galilei 
humbly begs your Holiness to exchange the place 
assigned to him for his prison near Rome for some 
other in ^ Florence, which may appear suitable to 
your Holiness, in consideration of his poor health, 
and also because he is expecting a siste^ [in law] 
with eight children from Germany, to whom no 
one can afford help and protection so well as 
himself. 2 He will receive any disposition of your 
Holiness as a great favour." 

But at the Vatican it was thought that to 
allow Galileo to return at once to Florence 

1 See p. 156 ante, and the Bibliography at end. 

2 A pretext, see " Galileo e Suor Maria Celeste," p. 188. 


would be a superfluity of indulgence. "We 
must proceed gently/' said his Holiness, "and 
only rehabilitate him by degrees/' Still Urban 
was moved to some compassion, and on 3oth 
June allowed the poor old man to retire to 
Siena, to the house of his former pupil Arch- 
bishop Ascanio Piccolomini, where he was to 
remain under the orders of the Archbishop, and 
on no account to leave the town without per- 
mission from Rome. Galileo was informed of 
this decision on 2nd July, and early on the 6th 
he shook the dust of Rome from off his feet 
Niccolini, reporting his departure to Cioli (on 
loth July), says: "Signor Galileo set out early 
on Wednesday in good health for Siena, and 
writes to me from Viterbo that he had performed 
four miles on foot, the weather being very cool." 

Galileo reached Siena safely on 9th July, 
and was warmly received by Piccolomini ; but 
neither his devoted kindness, not the stimulating 
converse with an old friend, the learned Alessandro 
Marsili, then residing at Siena, could make him 
forget that he was a prisoner of the Inquisition. 

On 23rd July 1633, he wrote to Cioli : 

" To-day I address myself to you, oppressed 
by the ennui of a captivity of more than six 
months a captivity made more painful by the 
chagrin and the anxiety of the preceding year, 
and by all the dangers and all the bodily sufferings 
which have followed in their train. My misfortunes 
are commiserated by all the world, except by 
those who have judged me deserving of this 
punishment but of this another time. 

"The duration of my captivity is entirely at 

332 EXILED TO SIENA [1633 

the pleasure of his Holiness. On the intervention 
of the Ambassador Niccolini, the Pope assigned 
me, instead of the prison of the Holy Office, 
the Villa de Medici, Trinita dei Monti, where I 
remained some days. Again, on the Ambassador's 
intercession, I was sent to the Archiepiscopal 
Palace here, where for fifteen days I have 
experienced the greatest kindness from the 
excellent Archbishop. But, apart from the wish 
that I have to return to my home and to be at 
liberty, this liberty is really essential to me. 
Therefore, I beg you to move his Highness to 
solicit the favour of my liberty from his Holiness, 
or through Cardinal Barberini. You might point 
out that the house of the Grand Duke has been 
for a long time deprived of my services, and insist 
on attaching to this circumstance more importance 
than it merits/' 

After all his bitter disillusions we see that 
his hopefulness had not yet abandoned him. The 
Grand Duke very kindly consented to exert once 
more what influence he possessed with the Pope, 
and instructed his ambassador accordingly; but 
Niccolini represented that the moment was not 
opportune, and recommended that action should be 
deferred for a few months. Meanwhile the good 
Archbishop did all that love for his venerated 
guest could suggest to make his house as little 
like a prison as possible, rather "an earthly 
paradise," as Maria Celeste wished her father 
to consider it; but for a long time these efforts 
had little effect The cruel edict condemning 
him to perpetual silence on a subject which was 
one of the mainsprings of his life was a serpent's 
sting which could not be readily forgotten ; his 


soul was lacerated, and he fell into frequent fits 
of utter despondency, in which he accused his 
friends of having forgotten him. In one of these 
moments of bitterness he wrote to his daughter 
"my name is erased from the book of the living." 
"Nay," came Maria Celeste's soothing reply, "say 
not that your name is struck out de libro 
viventium, for it is not so, neither in the greater 
part of the world, nor in your own country. 
Indeed, it seems to me that if for a brief moment 
your name and fame were clouded they are now 
restored to greater brightness ; at saying which 
I am much astonished with myself, for I know 
that generally nemo propheta acceptus in patria 
sua. I am afraid that if I go on quoting Latin 
I shall fall into some barbarism, so I shall stop. 
But, indeed, you are loved and esteemed here 
more than ever." 

As the weary months rolled on, Galileo became 
a little resigned to his situation at Siena, and 
even began to occupy himself with another of 
his great works (indeed the greatest), namely 
" Dialoghi delle Nuove Scienze" (or, Dialogues on 
The New Sciences), the writing of which he spoke 
of as far back as 1610, in his letter to Vinta. His 
interest in other scientific matters was as keen as 
ever. Thus, writing (27th September) to Andrea 
Arrighetti, a young Florentine disciple who had 
sent him some mathematical problems, he says : 

"The pleasure with which I read and re-read 
your demonstrations was greater than my astonish- 
ment, since the pleasure was proportionate to 
the sagacity of which you give proof in your 

334 EXILED TO SIENA [1633 

argumentation, while the astonishment was little, 
because I remembered I had under my eyes a 
work of Signor Andrea Arrighetti. 

"The last theorem held" me for a moment 
in meditation and in doubt, as much owing to 
the unusual formula as to fatigue of memory, 
which lets escape impressions as soon as formed. 
Let this be a lesson to you, and encourage you 
to exercise the mind while you are young. 

" As regards myself, I can say that my relations 
with my kind and honoured host bring me much 
consolation, and in the midst of so many sad 
subjects for meditation they give a new direction 
to my thoughts. But more than any other 
consolation, the knowledge that you and my other 
friends retain for me your old affection makes my 
grief less heavy/' 

Galileo's detention at Siena would, perhaps, have 
been borne more easily did he not know that his 
loved and loving daughter, in spite of her resigna- 
tion, was consuming her poor heart with longing to 
see him once more. " When you were in Rome I 
said to myself, if he were but at Siena ! Now you 
are at Siena, I say, would he were at Arcetri ! But 
God's will be done!" Her life was one continual 
prayer for him. Yet, while ever thinking of his 
spiritual welfare, she did not neglect his worldly 
affairs. In her letters of this period she tells him 
of the fruit and the wine which have been sold ; 
of the incoming and outgoing of his money ; that 
the vines had been injured by hail; that thieves 
had been over the garden wall ; that his mule was 
behaving badly and would carry no one now her 
master was away; that a storm had damaged the 
roof, an.d thrown down and smashed a large vase ; 


that the plums were few; and that the wind had 
carried away the pears; and so on. With the 
money from the sale of some lemons she had had 
three masses said for her father's special benefit. 
Finally: " there are two pigeons/ 5 she says, "in 
the dovecot waiting for you to come and eat them ; 
there are beans in the garden waiting for you to 
gather them ; and your tower is lamenting your 
long absence." 

As soon as the quarantine regulations were 
relaxed, Maria Celeste sent the boy Geppo on the 
mule to Siena to bring back news of her father, 
how he was looking, etc. The poor old man seems 
to have asked her to remember him in her prayers, 
for on Geppo's return she wrote (3rd October) : 

" It seems to me a thousand years till I see you 
back again safe and well. I would not have you 
doubt that all this time I have never ceased from 
commending you to God with my whole heart, for, 
indeed, I feel too anxious for your spiritual and 
bodily health ever to have neglected praying for 
you. To give you a proof I will tell you that 
as a great favour I had a copy of your sentence 
shown to me, and though on the one hand it 
grieved me to read it, yet on the other hand I 
was glad, because I found out a way of being 
of some slight use to you, namely, by taking on 
myself that part of the sentence which orders you 
to recite the seven Penitential Psalms once a week. 
I began to do this a while ago, and it gives me 
much pleasure first, because I am persuaded that 
prayer in obedience to Holy Church must be effi- 
cacious ; secondly, in order to save you the trouble 
of remembering it. If I had been able to do 
more, most willingly would I have entered a straiter 

336 EXILED TO SIENA [1633 

prison than the one I live in now, if by so doing 
I could set you at liberty." 

At length, the weariness and sickness of heart 
caused by hope deferred began to tell on this sweet 
nun. Worn by continual ill-health, by anxiety for 
her father, by nightly watchings in the convent 
infirmary, and daily occupations in the stillroom 
and pharmacy, she would appear to have felt a 
presentiment of her approaching dissolution. She 
strove gently to prepare her father, telling him 
it was for him to live long to the service and the 
glory of the God who had endowed him with such 
a wondrous intellect, and to the comfort of many 
who would feel his loss. As for herself, she could 
neither do much for the glory of God, nor be of 
much use to any one, and her living or dying would 
make little difference. 

In November 1633, thinking the time favour- 
able, Niccolini began to agitate for Galileo's pardon, 
but the Pope was not disposed to go so far, and 
pretended there would be a difficulty in getting 
the Congregation of the Holy Office to consent to 
such a course a patent evasion, as the decision 
rested solely and entirely with himself. Niccolini, 
however, persisted in his efforts, and went to 
Cardinal Barberini and other members of the 
Congregation to enlist their good .offices. At 
length, on 1st December, the question of Galileo's 
pardon, or rather release from personal restraints, 
came before the Congregation the Pope pre- 
siding and, though recommended by Cardinal 
Barberini, it was refused; but Galileo was per- 


mitted to retire to his villa at Arcetri, where 
he was to remain till further orders, and where 
he might receive his friends and relations, but 
not too many at a time, if he wished to avoid 

While Niccolini's letter of 3rd December, con- 
taining this piece of good news, was on its way 
to Siena, Galileo was writing thus to Bocchineri 
in Florence (gth December) : 

" For the last four days I have suffered from 
violent pains in the limbs which are more persistent 
than ordinary. I fear greatly that this climate (much 
more rigorous in winter than that of Florence) is 
the principal cause of these ailments ; and I foresee 
that I shall be very seriously crippled if obliged 
to remain here much longer. I await a decision 
from Rome, but I have little hope of its being 

For once Galileo despaired, and at the wrong 
moment! The same day Niccolini's letter of 3rd 
December arrived, and a few days afterwards he 
set out for Arcetri. 




ON returning to his villa, II Giojello, after nearly 
a year's absence, Galileo's first care was to visit 
his daughters in the neighbouring convent of San 
Matteo ; and afterwards, and when permitted to 
do so by the local Inquisitor, this was his greatest 
pleasure. But alas ! this man of sorrows was soon 
to taste again the cup of affliction. When Maria 
Celeste heard that her father's prison had been 
changed to Arcetri, and that he may be expected 
in a few days, she hardly had strength enough 
to be glad. 

" I do not think," she wrote on 3rd December, 
" that I shall live to see that hour. Yet may God 
grant it if it be for the best." 

Her prayer was granted and hardly more. 
Before she lay down, weary and prematurely old, 
in her narrow bed in the little convent chapel, 
she was able to embrace her dearest Lord and 
father. What passed between those two sorely- 
tried and loving souls in the last few and suffering 

1634-1636] DEATH OF MARIA CELESTE 339 

weeks of the daughter's life it would be profanity 
to attempt to describe, even if we knew. 

Sister Maria Celeste died on 2nd April 1634, 
in her 34th year, having been born on 1 3th August 
1600. The rest that we know of her will best 
be given in the words of her heart-broken father. 
Writing to his friend, Elia Diodati, Paris, on 25th 
July 1634, he says: 

" I hope that when you hear of my past and 
present misfortunes, and my anxiety about those 
perhaps still to come, it will serve as an excuse to 
you and my other friends and patrons in Paris ; to 
you for my long delay in answering your letter, and 
to them for my entire silence. According to the 
sentence pronounced on me by the Holy Office, 
I was condemned to imprisonment during the 
pleasure of his Holiness, who was pleased, 
however, to assign the palace and gardens of 
the Grand Duke near the Trinita dei Monti as 
my place of imprisonment As this was in June 
of last year, and I had been given to understand 
that if I asked for a full pardon after the lapse of 
that and the following month I should receive it, 
I asked, meanwhile, to avoid having to spend the 
whole summer and, perhaps, part of the autumn 
there, to be allowed, on account of the climate, to 
go to Siena, where the Archbishop's house was 
assigned to me as a residence. I stayed there 
five months, when this durance was exchanged for 
banishment to this little villa, a mile from Florence, 
with a strict injunction not to go to the city, and 
neither to receive the visits of many friends at once, 
nor to invite any. 

"Here, then, I was living, keeping perfectly 
quiet, and paying frequent visits to a neighbouring 
convent where two daughters of mine were living as 


nuns. I was very fond of them, especially of the 
elder who possessed extraordinary mental gifts, 
combined with rare goodness of heart; and she 
was very much attached to me. During my 
absence, which she considered very perilous for 
me, she fell into a profound melancholy which 
undermined her health, and she was at last attacked 
by a violent dysentery of which she died after six 
days' illness, just thirty-three years of age, leaving 
me in the deepest grief." 

Galileo was so overwhelmed by her death that 
it seemed to him as if he were destined speedily to 
follow her. "I hear her constantly calling me," 
he wrote to Geri Bocchineri on 27th April In 
the rest of this letter we have a sad picture of the 
old man's desolation. From some alarming bodily 
symptoms, and his daughter's call resounding in his 
ears, he believed himself to be dying. 

"I am going to write to you," he says, "about 
my health which is very bad. I suffer much more 
from the rupture than has been the case before. 
My pulse intermits, and I have often violent palpi- 
tation of the heart. Then, the most profound 
melancholy has come over me ; I have no appetite 
and loathe myself; in short I feel myself perpetually 
called by my beloved daughter. 

" Under these circumstances I do not think it 
advisable that Vincenzio should set out on a journey 
now ; as events might occur at any time which 
might make his presence desirable ; for, besides 
what I have mentioned, continued sleeplessness 
alarms me not a little. I tell you this that you 
may tell him if you think fit not because I wish to 
disturb his plans, but because it seems to me that 
he ought to know. You, who can speak more 
firmly to him than I can, will say enough to make 


him take the course which is most advisable. He 
has been asking for his allowance, 25 crowns; 
I enclose it to you to forward to him, as I do not 
want to say a single word, for him to turn and twist 
at his pleasure." 1 

As we see from the letter just quoted, Galileo 
was at this time suffering much from one of his 
many complaints (hernia). On its recurrence 
earlier in the year, he sought permission 
through the Tuscan Ambassador to move into 
Florence for the sake of the regular medical 
treatment which his case required, and which 
he could not well have at the villa outside the 
city. As if to dye his tragic fate still darker, he 
received the answer to this petition at the same 
moment that the physician told him of the ap- 
proaching death of Maria Celeste. In the letter to 
Diodati above quoted, he says : 

" My grief at this terrible news was increased 
by another calamity. On returning home from the 
convent with the doctor who visited my sick 
daughter shortly before her death, and who had 
just told me that her situation was desperate, and 
that she would hardly survive till the next day (as 
indeed it proved), I found the Inquisitor's vicar 
here, who informed me of a mandate from the Holy 
Office that I must in future abstain from asking 
permission to return to Florence, or they would 
take me back to Rome, and put me in the actual 
prison of the Holy Office. 2 From this answer it 

1 Vagabond still, Vincenzio was at this time living in Florence in 
a house which his father had settled on him in the Via della Costa, 
and close to the Porta San Giorgio. 

2 This savage mandate was dictated by the Pope at a meeting 
held on 23rd March. 


seems to me that in all probability my present 
prison will only be exchanged for that narrow and 
long-enduring one which awaits us all." 

He then goes on to give his correspondent 
some interesting information which allows us to 
see a little behind the scenes of this terrible 
drama : 

" From this and other circumstances which it 
would take too long to describe, it will be seen that 
the fury of my powerful persecutors continually 
increases. They have, at length, chosen to reveal 
themselves to me. Thus, about two months ago 
when a dear friend of mine at Rome was speaking 
of my affairs to Father Cristoforo Griemberger, 
mathematician at the Collegia Romano, this Jesuit 
uttered the following precise words : 'If Galileo 
had only known how to retain the favour of the 
fathers of this college he would have stood in 
renown before the world, he would have been 
spared all his misfortunes, and could have written 
what he pleased about everything even about the 
motion of the earth/ From this you will see, 
honoured Sir, that it is not this opinion or that 
which has brought and still brings about my 
calamities, but my being in disgrace with the 
Jesuits . . . . * Add to all this other troubles 
and many bodily infirmities which, without 
mentioning my age (more than seventy years), 
so overwhelm me that the least fatigue 
exhausts me and makes me ill. For all these 
reasons my friends must be indulgent and re- 
member that that which at first sight seems to 
be negligence is in reality only powerlessness. 

"But you, honoured Sir, who more than any 
other have wished me well, you will keep me in the 
affection of all my friends in Paris, especially of 


Signer Gassendi whom I love and venerate so 
much. Please communicate to him the contents of 
this letter, and tell him also that I have received the 
dissertation of Signor Martius Hortensius [on the 
double motion of the earth], and that I have read it 
with the very greatest interest. If it please God to 
deliver me from a part of the evils which I endure 
at this moment, I shall not fail to answer his amiable 

" Berigard and Chiaramonti, 1 professors at Pisa, 
have written long works against me the latter in 
his own defence ; the former against his wish, as he 
says, but at the instigation of one who may be 
useful to him ! A certain Jesuit father has printed 
at Rome that the opinion of the motion of the earth 
is of all heresies the most abominable, the most per- 
nicious, the most scandalous ; and that one may 
maintain in professorial chairs, in society, in public 
discussions, and in books, any and every argument 
against the principal articles of faith, against the 
immortality of the soul, against the creation, against 
the Incarnation, against everything, with one ex- 
ception only the dogma of the immobility of the 
earth ! The title of this production is ' Melchioris 
Inchofer a Societate Jesu Tractatus Syllepticus.' 2 It 

1 This man was one of the most bigoted defenders of the old 
philosophy, and, as Montucla says, spent a long life in nothing but 
retarding as far as he was able the progress of science. He was one of 
the Commission appointed in 1632 to get up the case against Galileo. 
(See also footnote, p. 256 ante.) 

2 This work was lauded by his brother Jesuits "as differing so 
entirely from the pruriency of the Pythagorean writings." Quoting 
the first verse of Genesis as an argument that the earth was created 
after the heavens, he says the question is reduced to a purely geo- 
metrical problem. In the formation of a sphere does the centre or the 
circumference come first ? If the latter, the consequence is inevitable, 
the earth is in the centre of the universe ! The title-page of this book 
is decorated with an emblematical figure, representing the earth in a 
triangle j and in the three corners, grasping the globe with their fore 
feet, are the three bees of the Pope's arms, with the .motto, "ffis fixa 
quiescit " (fixed by these it is at rest). 


is from Rome also that Antonio Rocco writes in 
defence of the peripatetic philosophy, and with such 
little consideration fpr me. He acknowledges, him- 
self, that he knows nothing of mathematics or 
astronomy. He has, in fact, not the least notion 
of the subjects on which he writes. 1 

" If God wills, I hope to publish my works on 
Motion, and other researches all more important 
than those which have already appeared. This 
letter will reach you through my relative Roberto 
Galilei, to whom you might read it, as I have 
written to him only very briefly. ..." 

Full of labour and of sorrow his life had been, 
and full of labour and sorrow it was to continue to 
the end. Though crushed by grief for his 
daughter's death, the habits of industry acquired 
in youth, and maintained through life, could not be 
laid aside in old age. Work to his teeming mind 
was more than a consolation, it was a necessity. 
Thus it is that but a few months after Maria 
Celeste's death, we find him rousing himself, and 
eagerly at work again on his new Dialogues, 
wishing, as he told Diodati, that the world should 
see the last of his labours before his time of depar- 
ture came. But, as he wrote, thoughts crowded 
thick and fast upon him, so that his work increased 
while each day lessened his span of life. "My 
restless brain goes grinding on," he wrote to 
Micanzio on igth November 1634, ' ( ' m a wa y that 
causes great waste of time, since the thought, which 
comes last into my head in respect of some novelty, 
drives out all that had been there before." He also 

1 For a list of anti-Copernican works published between 1632 and 
the time of Newton, 1668, see Martin's " Galilee," note B. 


resumed his extensive correspondence with scientific 
friends. Unfortunately, few of his letters of this and 
the following year have come down to us, so that we 
can only infer the subjects from the answers of his 

While the prisoner of Arcetri was thus fulfilling 
his great mission, his friends took every opportunity 
of trying to obtain, at least, some extension of 
his liberty. Niccolini, Comte de Noailles (French 
Ambassador), and Niccolo de Peiresc (in letters 
from Paris), all interceded again and again with the 
Pope, but all to no purpose. His Holiness had soft 
words for all of them, but nothing was done. 1 

How deep was the undercurrent of bitterness in 
Galileo's heart when stirred by the remembrance of 
the Jesuits* machinations, his " wretched enemies," 
as he calls them, his correspondence of this period 
sufficiently shows. We give some extracts from 
his letter to Niccol6 de Peiresc, 2ist February 
1635. After warm thanks for the noble though 
fruitless efforts of his friend, he goes on : 

" I have said, my Lord, that I hope for no 
alleviation, and this is because I have committed no 
wrong. 2 If I had erred I might hope to obtain 
grace and pardon, since the transgressions of the 
subject are. the means by which the prince finds 
occasion for the exercise of mercy and indulgence. 
Wherefore, when a man is wrongly condemned to 
punishment, it becomes necessary for his judges to 

1 De Noailles was formerly a private resident pupil of Galileo at 
Padua, and de Peiresc was a friend of Phrelli at whose house Galileo 
often met him. 

8 " Forgiveness to the injured does belong, 

But they ne'er pardon who have done the wrong." 

DRYDEN, Conquest of Granada. 

346 THE NEW SCIENCES [1634- 

use the greater severity in order to cover their own 
misapplication of the law. . . , Could all the frauds, 
the calumnies, the stratagems, the deceits, which 
were made use of at Rome eighteen years ago for 
the purpose of imposing on the supreme authority 
could all these, I say, be brought to light, their only 
effect would be to enhance the purity and upright- 
ness of my intentions. But you, having read my 
works, will have seen how they justify my assertion 
of sincerity, and you will have understood the true 
cause for which, under the mask of religion, I have 
been persecuted, and which now continually assails 
me and crosses my path, so that no help can come 
to me from without ; nor can I undertake my own 
defence, all the Inquisitors having received ex- 
press orders neither to allow the reprinting of my 
published works, nor to grant a licence for any 
fresh work I may wish to publish. Thus I am not 
only reduced to silence towards those who strive to 
distort my opinions, and so to make my ignorance 
(as they call it) manifest, but I must also bear the 
insults, the contempt, and the bitter taunts of men 
more ignorant than myself, without being able to 
utter a word in my own defence. " 

The Dialogues on The Two New Sciences (i.e. 
on Cohesion and Resistance to fracture, and on 
Uniform, accelerated, and projectile motion) were 
completed by the summer of 1636, and then arose 
the question of their publication. After his con- 
demnation in 1633, the Holy Office placed his name 
in the list of authors whose writings edita et edenda 
were strictly forbidden, and so rigorously was 
this rule enforced, that Micanzio was not permitted 
to reprint the " Discourse on Floating Bodies," 
which did not in any way relate to the Copernican 
doctrines. Galileo tried Germany, and sent the 


MS. to his friend Giovanni Pieroni in Vienna, only 
to find that all books printed there must first 
be sanctioned by the Jesuits, amongst whom at 
the moment Galileo's old antagonist, Father 
Scheiner, happened to be quartered. So Vienna 
would not do. Through the intervention of 
Cardinal Dietrichstein, Pieroni then got permission 
to print at Olmutz, with the approbation of a 
Dominican father, so that the business may be 
kept secret from Scheiner and his party. But 
very soon after, the Cardinal died, and, besides, 
Pieroni was not pleased with the Olmutz press, 
so the MS. was brought back to Vienna. A new 
approbation was procured (Scheiner having gone 
meanwhile into Silesia) and the work was on 
the point of being sent to the press when the 
dreaded Scheiner reappeared. Pieroni next took 
the MS. to Prague, where Cardinal Harrach 
offered him the use of the University press ; but 
here again difficulties cropped up. Meanwhile 
Galileo, wearied with these delays, opened negotia- 
tions with Louis Elzevir through Micanzio in 
Venice, and, finally, the work appeared at 
Amsterdam in 1638. 

It is clear from Galileo's correspondence that 
this edition was printed with his full concurrence, 
although, in order to obviate trouble with Rome, 
he pretended that it was pirated from a MS. 
copy which he had sent to Comte de Noailles, 
tb whom the work is dedicated. 

Rightly did Galileo, in his letter to Vinta of 
7th May 1610, call his work in mechanics a new 
science invented by him from its very first 

348 THE NEW SCIENCES [1634- 

principles. That this is no exaggeration is shown 
by the following passage from the " M^canique 
Analytique" of Lagrange, the great Italian 
Mathematician, and an undoubted authority on 
the subject : 

" Dynamics is the science of forces accelerated 
or retarded, and of the various movements which 
these forces can produce. This science is due 
entirely to the moderns, and Galileo is the one 
who laid its foundations. Before him philosophers 
considered the forces which act on bodies in a 
state of equilibrium only; and, although they 
could only attribute in a vague way the accelera- 
tion of heavy bodies, and the curvilinear move- 
ment of projectiles, to the constant action of 
gravity, nobody had yet succeeded in determining 
the laws of these daily phenomena on the basis 
of a cause so simple. Galileo made the first 
important steps, and thereby opened a way, new 
and immense, to the advancement of mechanics 
as a science. 

" These discoveries did not bring to him 
while living as much celebrity as those which 
he had made in the heavens ; but to-day his 
work in mechanics forms the most solid and 
the most real part of the glory of this great 
man. The discovery of Jupiter's satellites, of 
the phases of Venus, of the Sun-spots, etc., required 
only a telescope and assiduity; but it required 
an extraordinary genius to unravel the laws of 
nature in phenomena which one has always 
under the eye, but the explanation of which, 
nevertheless, had always baffled the researches 
of philosophers." 

The Dialogue is carried on between the same 
speakers, Salviati, Sagredo, and Simplicio, as in 


the " Dialogues on the Two Principal Systems 
of the World " (1632). The first two of the 
four Dialogues published in his lifetime are 
concerned with the " Resistance of Solids against 
Fraction/' and the " Cause of Coherence in 
Solids." The ostensible object of the first 
discussion was scarcely reached, while the second 
contains little beyond an analysis of formulae 
concerning the strength of beams. Their scientific 
value lies in the incidental experiments and obser- 
vations on motion through resisting media. 

The discussion opens with a short examination 
of the current belief that models built on exactly 
similar designs but on different scales were of 
strength in proportion to their linear dimensions. 
After exposing the error, Salviati enquires what 
is the nature of the force that holds up the lower 
part of a rod suspended from above. No complete 
explanation is forthcoming; but that suggested 
depends upon Nature's repugnance to the vacuum 
momentarily produced by the sudden separation 
of two flat surfaces. This leads to an experiment 
proposed by Salviati for measuring what he speaks 
of as the force of a vacuum. 

This experiment occasions a remark from 
Sagredo that he had observed that a pump would 
not work when the water in the cistern had sunk 
35 feet below the valve; that he thought the 
pump was injured, and sent for the maker, who 
assured him that no pump of that construction 
would lift water from so great a depth. This 
story is usually told as if Galileo had said jokingly 
that Nature's horror of a vacuum does not ex- 

350 THE NEW SCIENCES [1634- 

tend beyond 35 feet. 1 He evidently shared the 
common notion of suction, for he compares the 
column of water to a metal rod suspended from 
its upper end, which may be lengthened till it 
breaks by its own weight. It is remarkable 
that he failed to observe how simply this pheno- 
menon may be explained by a reference to the 
weight of the atmosphere a fact with which 
he was well acquainted, and, indeed, goes on 
in this dialogue to describe an experiment for 
determining the weight of air as compared with 

water. 2 

After a rather lengthy digression on the motion 
of a rolling circular hoop, in which Galileo brings 
forward some truths probably new at the time, 
but not essential to the main subject of the present 
dialogues, we come to more important matter 
in the discussion of motion through resisting 
media. This is introduced by some vague 
suggestions as to the nature of the action of 
heat on solid bodies, leading on to a short 
reference to light phenomena, which, Salviati 
insists, imply motion through a medium of some 

This statement introduces Aristotle's theory 
that bodies move with velocities proportional to 
their weights and inversely proportional to the 
densities of the media through which they are 

1 The first appearance of the story in this form has been traced 
to Pascal's "Traitez de Tequilibre des Liqueurs" (preface), Paris, 

a Galileo'? way of determining the specific gravity of the air 
was first described in his letter to Gio. Battista Baliani, dated 
I2th March 1613, now in the Brera Library, Milan. 


moving. This proposition is examined in a strict 
scientific method. Heavy bodies of different 
weights are dropped in air to test the truth of 
the first part of the statement ; and afterwards 
the motion of bodies rising or falling in liquids 
is considered ; the result being to Substitute for 
Aristotle's hasty assumption that law of the motion 
of falling bodies which is historically the founda- 
tion of the science of dynamics. 

Two stones are dropped in air ; their weights 
are respectively eight and four units. Aristotle's 
theory requires that the first shall travel with 
twice the velocity of the second; that, in fact, if 
the second have four, then, the first will have 
eight degrees of velocity. Salviati states that this 
does not agree with experiment; but he further 
reduces the dictum to an absurdity by considering 
the effect of fastening the two stones together. 
Common-sense would have it that the result would 
be a hurrying of the slower and a delaying of the 
faster traveller, producing a mean velocity of some- 
where between four and eight velocity-units. 
Actual experiment would show that, according 
to the manner of fastening and the shape and 
distribution of weight in the stones, it might be 
possible to obtain a velocity slightly in excess of 
that of the heavier stone when falling alone. But 
neither common-sense nor experiment agrees with 
Aristotle's statement, according to which the 
compound body, now containing twelve units of 
weight, ought to travel with twelve units of velocity. 
So far, indeed, is Aristotle from the truth that 
Salviati asserts that if a stone weighing twenty 

352 THE NEW SCIENCES [1634- 

pounds and another weighing two pounds be 
dropped simultaneously from a tower 50 or 100 
yards high, they will reach the earth at the very 
same moment. 

"And I would not have you do as some are 
wont, who fasten upon some saying of mine that 
may want a hair's breadth of the truth, and under 
this hair seek to hide another man's blunder as big 
as a cable. Aristotle says that an iron ball weigh- 
ing 100 Ibs. will fall through a space of 100 
yards while a weight of one pound is falling 
through a space of one yard. / say they will 
reach the ground together. They find the greater 
weight to anticipate the lesser by two inches, and 
under these two inches they seek to hide Aristotle's 
99 yards ! " 

So Galileo satisfied himself that the current 
belief was wide of the truth ; and that it was more 
nearly correct to say that heavy bodies, dropped 
through the air, fell with the same increasing 
velocities, whatever their weights, provided only 
those weights were sufficient to overcome with 
ease the air's resistance to their motion. He 
proceeds to examine the motion of bodies sinking 
or rising in water and other liquids ; and he brings 
forward a group of experimental facts which, viewed 
in the light of Aristotle's statement, form a mass of 
contradiction. Putting this antiquated theory aside, 
Salviati enquires what is meant by the rising of 
some bodies in a medium, and shows that only 
those bodies rise which are lighter than the 
medium. The rising of an inflated bladder in the 
air suggests that the atmosphere must have 
weight. Simplicio's assertion that it is on the 


contrary the bladder in this case that has levity is 
trivial, and is immediately disproved. Continuing 
his line of argument, Salviati points out that the 
question of rising or falling depends on the gravity 
of the medium as compared with that of the moving 
body ; further, that when the motion of the body, 
either upwards or downwards, has once commenced, 
the different media offer different resistances to the 
motion, the heavier media, such as quicksilver and 
water, interfering more than air with the motion of 
a body ; and we are thus led to the following 
summing-up by Salviati. 

"We have found the difference of velocities in 
movables of different gravities to be more and 
more as the media are more and more resisting ; 
thus, in a medium of quicksilver, gold does not only 
sink to the bottom more swiftly than lead, but it is 
the only thing that will sink in it, all other metals 
and stones moving upwards therein and floating on 
its surface. Whereas between balls of gold, lead, 
brass, or any other heavy matter, the inequality of 
their motion in the air shall be almost wholly 
insensible, so that, indeed, a ball of gold falling from 
a height of 100 yards in the end of its fall does not 
outstrip one of wax by four inches." 

And then comes Galileo's bold, but justifiable 
deduction : 

"This being so, I have thought that if the 
resistance of the media be wholly taken away, all 
matter would descend with equal velocity." 

This fundamental law once stated is amplified 
later on in the Dialogue, when Salviati explains 
that : 

354 THE NEW SCIENCES [1634- 

" A heavy body has by nature an intrinsic force 
or principle of moving towards the common centre 
of heavy things (the centre of the earth) with a 
motion continually accelerated in such manner that 
in equal times there are always equal additions of 
velocity. This is to be understood as holding true 
only when all accidental and external impediments 
are removed, amongst which is one that we cannot 
obviate, namely, the resistance of the medium. 
This opposes itself more or less according as it 
opens slowly or speedily to make way for the 
moving body, which, being continually accelerated, 
encounters a continually increasing resistance in the 
medium, until at last the velocity reaches that 
degree and the resistance that power that they 
balance each other. All further acceleration is then 
prevented, and the movable continues for ever after 
with a uniform and equable motion." 

The description of the motion of a falling body 
in the first Dialogue is followed by a reference to the 
oscillation of a pendulum ; and this in turn leads to 
a digression, in which Galileo quotes a number of 
interesting experiments on sound. These it will be 
best for the present to pass over, as also the con- 
tents of the second Dialogue. The more important 
work in dynamics is resumed in the third and fourth 
Dialogues, on <{ Local Motion" and " Motion of 
Projectiles," the outline of which must be indicated 
in a few words. 

No new physical facts of importance are quoted ; 
these two Dialogues are mainly concerned with 
theorems and formulae deduced mathematically 
from the phenomena explained in the first Dialogue. 
The discussion of uniform motion, however, involves 
a more emphatic statement than before of the prin- 


ciple of inertia that a body projected along a 
smooth horizontal plane would, if all resistances and 
external impediments were removed, continue to 
move uniformly along that horizontal plane for ever. 
Generalised, this statement would be equivalent to 
Newton's first law of motion. From the definition 
of uniform motion as that of a body which moves in 
one direction so as to cover equal spaces in equal 
intervals of time, Salviati proceeds to deduce the 
elementary formulae, which his two listeners readily 

The definition of uniformly accelerated motion, 
however, at once introduces a difficulty. Salviati 
gives the correct description of it as that of a body 
which moves in such a manner that in equal intervals 
of time it receives equal increments of velocity. An 
alternative is suggested by Sagredo, and Simplicio 
sympathising as usual with Sagredo's untenable pro- 
positions is of course " of the number of those who 
allow that a descending body vires acquirit eundo " ; 
in fact, that the increments of velocity should be 
specified in relation to ? the space rather than the 
time through which the body has travelled. They 
first appeared to think that the two statements would 
be equivalent and that theirs took the more direct 
form. It is pointed out by Salviati that the two are 
inconsistent, and he rightly conjectures that a direct 
reference of acceleration to the space described rather 
than to the time of travelling would lead to hopeless 
complications. He proceeds, accordingly, from his 
own definition to deduce formulae connecting all 
these variable quantities time of motion, velocity 
acquired, and space described with one another. 

3 $6 THE NEW SCIENCES [1634- 

An interesting application of the results obtained 
follows. He examines the times of descent down 
differently inclined planes, assuming as a postulate 
that the velocity acquired by a body falling down an 
inclined plane was the same for all planes of the 
same height. This fact he had verified by careful 
experiments, although he was unable at the time to 
account for it. 1 After the inclined plane comes an 
investigation of " lines of quickest descent " a 
group of interesting problems, though not of 
essential importance in the development of the 
science of dynamics. Here he shows that the 
descent of bodies along an arc of a circle of legs 
than 90 is shorter than the time occupied by the 
same bodies in traversing the chord of the arc 
"which at first sight would seem to be a paradox, 
the arc being longer than its chord/' 

This investigation completed, the way is prepared 
for the subject of the fourth Dialogue. Sagredo, 
anticipating mathematical difficulties, begs for some 
preliminary instruction in the properties of the 
parabola, after which Salviafei turns to the spbject of 
projectiles, and lays down the law of the independ- 
ence of the horizontal and vertical motions. A body 
projected horizontally would (but for its weight 
and " external impediments " which we suppose 
removed) continue to move ; and Salviati contends 
that as the effect of gravity acting by itself would 
be entirely downwards, gravity acting on the hori- 

1 Viviani relates that soon after he joined Galileo, he drew his 
master's attention to this flaw in the argument. The same night, as 
Galileo lay in bed, sleepless through indisposition, he discovered the 
necessary mathematical demonstration. It was introduced into the 
subsequent editions of the Dialogues, Sixth " Day." 



zontally projected body can neither increase nor 
diminish the rate at which it travels horizontally. 
Therefore, whatever be the shape of the path or the 
real direction of motion at any moment, the horizontal 
part of the motion is uniform, and the distance 
travelled horizontally may, therefore, be taken as a 
measure of the time that has elapsed since motion 

Salviati proves that on this assumption the path 
described has geometrical properties which identify 
it with the curve known as the parabola. His 
demonstration is essentially that now given in 
works on elementary dynamics ; the present account 
of the dialogues would, however, be incomplete with- 
out a quotation of the proof in Galileo's form. 


Fig. 9. 

" Let A B represent a horizontal line or plane 
placed on high, on which let a body be carried 
with an equable motion from A towards B ; and 
the support of the plane being taken away at B, 
let the natural motion downwards due to the body's 
weight come upon it in the direction of the perpen- 
dicular B N. Moreover, let the straight line B E 
(a prolongation of A B) represent the flow or 

358 THE NEW SCIENCES [1634- 

measure of the time, on which let any number 
of equal parts B C, C D, D E, be marked, and 
from the points C, D, E, let lines be drawn parallel 
to B N. In the first of these let any part C I 
be taken, and let D F be taken four times as great 
as C I ; EH nine times as great, and so on. Now, 
if we suppose that whilst by its uniform horizontal 
motion the body moves from B to C, it also 
descends by its weight through C I, and at the 
end of the time denoted by B C it will be at I. 
In the time B D, double of B C, it will have fallen 
four times as far ; for in the first part of this treatise 
it has been shown that the spaces fallen through 
by a heavy body vary as the squares of the times. 
Similarly, at the end of the time B E, or three 
times B C, it will have fallen through E H, and 
will be at H. Now, it is plain that the points I, 
F, H, are in the same parabolical curve B, I, 
F, H." 

It only remains to verify whether the parabola 
as defined geometrically is actually the path of the 
moving body. This, as Salviati states, is true 
under certain conditions. Firstly, the path tra- 
versed must be of small dimensions as compared 
with the dimensions of the earth"; this is necessary 
in order that the horizontal direction and the 
direction of gravity may be the same throughout 
the motion. And secondly, the resistance of the 
air so far modifies the motion, that the true 
parabola is only possible on the supposition 
that motion takes place in vacuo ; the resist- 
ance of the air, however, is reduced to a 
minimum if we examine the motion of a heavy 
body of small dimensions travelling with only a 
moderate velocity. 


After demonstrating the parabolic nature of the 
path, Galileo enquires into certain points of interest 
with regard to it, and gives proofs of many of the 
elementary propositions which in modern text-books 
are associated with parabolic motion. He also 
draws up a table giving the position and dimensions 
of the parabola described with any given direc- 
tion of projection ; finding by this means what 
he would have been unable to give a strict 
mathematical proof of that the range on a hori- 
zontal plane is greatest when the angle of 
elevation is 45. 

The discussion of parabolic motion occupies the 
remainder of the Dialogue. Only one passage 
needs special mention. A bullet fired horizontally 
travels fast, yet not instantaneously; however 
rapidly it moves it takes time to travel even 
a short distance ; therefore gravity will draw it 
downwards, though ever so slightly, below the 
horizontal line which was its original direction. If 
.one. would hit a mark, it is, therefore, useless to 
fire straight at it. Sagredo had noticed this, and 
remarks also on what it appeared to him might 
be an allied phenomenon that a rope hanging 
between two points at the same height cannot be 
drawn absolutely straight however tightly it may be 
pulled. Salviati shows that this is due to the 
weight of the rope, just as the drop of the 
bullet is due to its weight He continues "as 
follows : 

" Besides, I must tell you that which at the 
same time will both amaze and delight you; 'tis 
this, that the rope, thus stretched more or less, 

360 THE NEW SCIENCES [1634- 

bends itself into lines very nearly parabolical. And 
the likeness is such, that if on a plane surface per- 
pendicular to the horizon you describe a parabolic 
line, and turn it upside down, and to the extremities 
of the base of the described parabola you hold a 
chain or cord, by slackening it more or less you'll 
see it bend and fit itself to the same parabola. 
And this fitting shall be so much the more exact 
by how much the described parabola is less curved, 
i.e., more distended ; so that in parabolas described 
at elevations less than 45 , the chain agrees with 
them almost to a hair." 

Galileo has sometimes been accused of having 
stated the curve of the suspended chain actually 
to be a parabola. From the passage quoted it is 
clear that the charge is unfounded. The catenary 
resembles the parabola ; and, as Galileo justly 
remarks, the resemblance is very striking if the 
string is so far taut that the depth of the lowest 
point is less than a quarter of the distance between 
the two extremities. Galileo's theory of dynamics, 
which we have traced briefly, constitutes the more 
important part of the Dialogues on the <c Two 
New Sciences." 1 

In order to preserve continuity, no reference has 
been made to the subject of the second Dialogue. 
It is an investigation of the strength of beams 
an amplification of his researches on the same 

1 "In solving the problems of falling bodies and of projectiles, 
Galileo was essentially applying the principles of the Differential or 
Fluxional or Indivisible Calculus. If pure mathematics had attracted 
him as strongly as its application to physks, he would have thought 
these problems out, and would have founded the Fluxional Calculus, 
which is the glory of N v ewton and of Leibnitz." Professor Jack in 
" Nature," vol. xxi. p, 58. See note, p, 120 ante. 


subject, dating back to 1609. Beyond Aristotle's 
remark that long beams are weak because they 
are at once the weight, the lever, and the fulcrum, 
nothing appears to have been written on the 
subject before Galileo took it up. In this he under- 
takes a problem which is far more intricate than 
he realised. A beam is fastened into a stone wall 
at one end and at the other supports a heavy 
weight; Galileo enquires into the strength of the 
beam to resist a snapping tendency. He assumes 
the point at which the fracture will take place to 
be close to the support. He further assumes that 
just before the moment of fracture the two parts 
of the beam will be holding together by means 
of a uniform force distributed uniformly over the 
section, as if the solid were equivalent " to a bundle 
of fibres/ 5 which were all strained equally in the 
direction of their length at the moment of snapping ; 
and this although the fracture is assumed to begin 
at the top, the lowest fibre being the last to give 

The curvature of a beam subject to any system 
of strains is a subject into which, before the days 
of Newton, it was impossible to enquire. And 
even in the simpler problem considered by Galileo, 
he makes assumptions which require justifying. 
Still, the discussion is interesting as the first serious 
attempt to examine this difficult statical problem. 
The formulae obtained, if they are wanting in detail, 
prove that, however vague Galileo's ideas of force, 
he fully realised the mathematical fact underlying the 
theory of models that if two frameworks are built 
on exactly the same plans but on different scales, 

362 THE NEW SCIENCES [1634- 

their strengths are not of necessity proportional 
to their dimensions. 

On the subject of light, Galileo has left very 
little in theory; his best work in this field was 
the invention of the telescope with which his name 
is universally associated. 

A suggestion in the first Dialogue that, perhaps, 
heat dissolves bodies by insinuating itself between 
their minute particles brings on the subject of 
light ; on which Sagredo enquires whether we are 
to take for granted that the effect of light does or 
does not require time. Simplicio is ready with an 
answer, that the discharge of artillery proves the 
transmission of light to be instantaneous ; to which 
Sagredo cautiously replies, that nothing can be 
gathered from that experiment except that light 
travels more swiftly than sound ; nor can we draw 
any decisive conclusion from the rising of the sun. 
"Who can assure us that he is not in the horizon 
before his rays reach our sight?" Salviati then 
mentions an experiment by which he endeavoured 
to examine this question. Two observers are each 
to be furnished with a lantern ; as soon as the 
first shades his light, the second is to uncover his, 
and this is to be repeated at a short distance till 
the observers are perfect in the practice. The same 
thing is then to be tried at the distance of several 
miles, and if the first observer perceive any delay 
between shading his own light and the appearance 
of his companion's, it is to be attributed to the 
time taken by the light in traversing twice the 
distance between them. He allows that he could 
discover no perceptible interval at the distance of 

i6 3 6] VELOCITY OF LIGHT 363 

a mile, at which he had tried the experiment, but 
recommends that with the help of a telescope it 
should be tried at much greater distances. 1 

The only other subject remaining to be noticed 
is the application of the theory of the pendulum 
to musical concords and dissonances, which are 
explained, in the same manner as by Kepler in 
his " Harmonice Mundi," to result from the 
concurrence or opposition of vibrations of the 
air striking upon the drum of the ear. It is 
shown that these vibrations may be made mani- 
fest by rubbing the finger round a glass set in a 
large vessel of water; "and if by pressure the 
note is suddenly made to rise to the octave above, 
every one of the undulations, which will be seen 
regularly spreading round the glass, will suddenly 
split into two, proving that the vibrations that 
occasion the octave are double those belonging 
to the simple note." Galileo then describes a 
method he discovered by accident of measuring 
the length of these waves more accurately than 
can be done in the agitated water. He was 
scraping a brass plate with an iron chisel, to take 
out some spots, and moving the tool rapidly upon 
the plate, he occasionally heard a hissing and 
whistling sound, and whenever this occurred, and 
then only, he observed the light dust on the plate 

1 This was done some years later by the Florentine Accademia 
del Cimento, with the result that as the observers became more 
expert the interval became shorter, so that there was no reason to 
suppose that there was any interval at all. In shorty light seemed 
to them to travel instantaneously. Roemer, the JDanish astronomer, 
first calculated in 1675 the velocity of light, and found it to be about 
200,000 miles per second, a close approximation to the modern figure, 
viz. 186,000. 

364 THE NEW SCIENCES [1634- 

to arrange itself in a long row of small parallel 
streaks equidistant from each other. In repeated 
experiments he produced different tones by scraping 
with greater or less velocity, and remarked that 
the streaks produced by the acute sounds stood 
closer together than those from the low notes. 
Among the sounds produced were two, which by 
comparison with a viol he ascertained to differ 
by an exact fifth; and measuring the spaces oc- 
cupied by the streaks in both experiments, he 
found thirty of the one equal to forty-five of the 
other, which is exactly the known proportion of 
the lengths of strings of the same material which 
sound a fifth to each other. 1 

Salviati also remarks that if the material be 
not the same, as for instance if it be required to 
sound an octave to a note on catgut on a wire 
of the same length, the weight of the wire must 
be made four times as great, and so on for other 
intervals. "The immediate cause of the musical 
pitch is neither the length, the tension, nor the 
thickness, but the proportion of the numbers of 
the undulations of the air which strike upon the 
drum of the ear, and make it vibrate in the same 
intervals of time, Hence we may gather a 
plausible reason for the different sensations oc- 
casioned in us by different couples of sounds, of 
which we hear some with great pleasure, some 
with less, and call them accordingly concords, more 
or less perfect; whilst some excite in us great 

1 This beautiful experiment has been largely used in modern 
times by Chladni, Savart, and Wheatstone, with very interesting 


dissatisfaction, and are called discords. The dis- 
agreeable sensation belonging to the latter, 
probably, arises from the disorderly manner in 
which the vibrations strike the drum of the ear; 
so that, for instance, a very harsh discord would 
be produced by sounding together two strings of 
which the lengths are to each other as the side 
and diagonal of a square, which is the discord of 
the false fifth. On the contrary, agreeable concords 
will result from these strings of which the numbers 
of vibrations made in the same time are com- 
mensurable, for then the cartilage of the drum 
does not undergo the incessant torture of a 
double inflexion which results from discordant 
percussions." The sense of pleasure in musical 
harmony involves questions which have yet to be 
answered. But Galileo's suggestion above has in 
it that degree of precision which distinguishes all 
his thought from that of the vague theorists of 
his day. 

Something similar may be exhibited to the eye 
by hanging up pendulums of different lengths. 
"If these be proportioned so that the times of 
their vibrations correspond with those of the 
musical concords, the eye will observe with 
pleasure their crossings and inter-crossings re- 
curring at appreciable intervals ; but if the times 
of vibration be incommensurate, the eye will soon 
be wearied in following them." 

No sooner was the MS. of these Dialogues 
out of his hands (summer of 1636) than Galileo's 
ever busy brain began to form new projects. 
"If I live," he wrote on isth July 1636, to 

366 THE NEW SCIENCES [1634- 

Bernegger of Strasburg, 1 " I intend to put in order 
a series of natural and mathematical problems which 
I think will be as curious as they are novel." 
These were left unfinished, and now form the 
fifth and sixth Dialogues which were added to a 
later edition by Viviani after Galileo's death. The 
fragment of the fifth is on the subject of Euclid's 
definition of ratio (Book V. props. 5 and 7), and 
was intended to form a part of the third Dialogue, 
and to follow the first proposition on equable 
motion. The sixth Dialogue was intended to 
embody Galileo's researches on the force of 
Percussion, on which he was employed at the 
time of his death. 

" In the last days of his life," says Viviani, " and 
amid much physical suffering, his mind was con- 
stantly occupied with mechanical and mathematical 
problems. He had the idea of composing two 
other Dialogues to be added to the four already 
published. In the first he intended to insert many 
new demonstrations and reflections on various 
passages in the first four Dialogues, besides the 
solution of many problems in Aristotle's physics. 
In the second he proposed to discuss, treating it 
geometrically, an entirely new science, viz. the 
wondrous force of percussion, which he claimed to 
have discovered, and which, he said, exceeded by 
a long way his speculations on the same subject 
formerly published " ("Vita di Galileo/' 1654). 

In these Dialogues in which Galileo recapitu- 
lates the results of his early mechanical researches 

1 The editor of the Latin edition of his Dialogues of 1632, which 
was brought out by the Elzevirs in 1635. The translation was really 
by Diodati of Paris, to whom Galileo had sent a copy of the work as 
first printed in Italian. 

i6 3 6] LAWS OF MOTION 367 

at Pisa and Padua, and of his life-long meditations, 
he does not formulate in definite laws the inter- 
dependence of force and motion. This was done 
for the first time by Newton at the beginning of 
his "Principia" (1687), and hence they are rightly 
called " Newton's Laws of Motion"; but in justice 
to Galileo it must be admitted that he not only 
prepared the way for Newton, but supplied him 
with much of his materials. Thus, the first law as 
stated by Newton that a body will continue in a 
state of rest, or of uniform motion in a straight line, 
until it is compelled to change its state from some 
force impressed upon it is a generalisation of 
Galileo's theory of uniform motion. Since all the 
motions that we see taking place on the surface of 
the earth .soon come to an end, we are led to 
suppose that continuous movements, such, for 
instance, as those of the celestial bodies, can only be 
maintained by a perpetual consumption and a 
perpetual application of force, and hence it was 
inferred that rest is the natural condition of things. 
We make, then, a very great advance when we 
comprehend that a body is equally indifferent to 
motion as to rest, and that it equally perseveres in 
either state until disturbing forces are applied. 
Such forces in the case of ordinary terrestrial 
movements are friction and the resistance of the 
air ; but where no such impediments exist, move- 
ment must be perpetual, as is the case with the 
heavenly bodies which are moving in a void, or 
something approaching it. 

The second law that every change of motion is 
in proportion to the force that makes the change, 

3 68 THE NEW SCIENCES [1634- 

and in the direction of that straight line in which 
the disturbing force is impressed is involved in his 
theory of projectiles. Before Galileo's time it was 
a commonly received axiom that a body could not 
be affected by more than one force at a time, and it 
was therefore supposed that a cannon-ball, or other 
projectile, moves forward in a straight line until the 
force which impelled it is exhausted, when it falls 
vertically to the ground. Galileo's writings in the 
fourth Dialogue and elsewhere show the fallacy of 
this axiom, since he demonstrates that the path of 
the projectile, being the result of a combination of a 
uniform transverse motion and a uniformly acceler- 
ated vertical motion, must, apart from the resistance 
of the air, be a parabola. 1 The establishment of 
this principle of the composition of forces supplied a 
conclusive answer to the most formidable of the 
arguments against the rotation of the earth, and, 
accordingly, we find it triumphantly brought forward 
by Galileo in the second " Day " of his Dialogues of 

The distinction between mass and weight was, 
however, not noticed, and, consequently, he failed to 
grasp that acceleration, which in the case of motion 
under gravity he so closely examined, might be 
made a means of measuring the magnitude of the 
force producing the motion. How far he was from 
this discovery may be gathered from a remark by 
Salviati incidental to the main argument, to the 
effect that when different bodies are falling freely 

1 In a vacuum it would be an ellipse. In fact, a projectile is a 
minute satellite of the earth, and in vacua it would accurately obey all 
Kepler's laws. 


towards the earth's centre, "the difference of their 
gravities has nothing to do with their velocities." 
Correct as this may be in the spirit in which it was 
meant, it shows that Galileo was yet far from 
anticipating in all its generality Newton's second 

Of the third of the laws of motion when a body 
exerts force on another, that other reacts with equal 
force ; action and reaction are always equal and in 
opposite directions we find traces in many of 
Galileo's researches, as in his theory of the inclined 
plane, and in his definition of momentum. It is 
also adumbrated in his " Delia Scienza Meccanica" 
(1594), and in his latest ideas on percussion, which 
he was dictating to his disciples, Viviani and 
Torricelli, when seized with his last and fatal 
illness. But that he was familiar with the 
relation between the blow on one body and the 
reacting blow on the other or striking body cannot 
be maintained. There is no precise statement to 
justify such a supposition. Indeed, Galileo's ideas 
of force, as they have come down to us, are so 
vague that a statement, at the same time precise 
and general, cannot be expected. 

Galileo's services were hardly less conspicuous 
in the statical than in the dynamical division of 
mechanics. He gave the first direct and entirely 
satisfactory demonstration of equilibrium on an in- 
clined plane. In order to demonstrate this he 
imagined the weight and the sustaining power to be 
applied to the ends of a bent lever whose arms 
were of equal length and perpendicular to the 
vertical and slant sides of the plane ; then reducing 

2 A 

370 THE NEW SCIENCES [1634- 

the lever to a straight one, between the lines of 
direction of the weight and power, it was easy to 
prove that the forces in equilibria on the plane were 
also in equilibria on the lever, and were to one 
another as the length to the height of the plane. 

By establishing the theory of " virtual velo- 
cities/' he laid down the fundamental principle 
which in the opinion of Lagrange contains the 
general expression of the laws of equilibrium. And 
as regards that still obscure subject, molecular 
cohesion, he brought it for the first time within the 
range of mechanical theory. 

As we have quoted Professor Playfair's apprecia- 
tion of the Dialogues of 1632, to make up for 
the shortcomings of our own rhumt, so with these 
still more admirable ones of 1638, we conclude with 
an extract which indicates the enduring value 
of Galileo's work in mechanics. Robert Grant, 
the distinguished astronomer, and author of the 
" History of Physical Astronomy/' says : 

" The astronomical discoveries of Galileo, 
although remarkable for their brilliancy, derive their 
chief value from the support they lent to the 
Copernican theory, and the influence they exerted 
in overthrowing the false system of philosophy 
which then prevailed. But it is in his important 
researches relative to mechanical science that the 
genius of this great philosopher is most apparent. 
The science of motion could not, indeed, be said to 
have existed before his time, for the sole knowledge 
on this subject consisted of a few unintelligible 
maxims scattered, through the works of Aristotle. 
It required no common degree of penetration to 
expose the errors which lurked amid the sophisms 
of the illustrious Stagirite ; but a genius of a higher 

1636] VALUE OF THE WORK 371 

order still was necessary to establish the clear and 
immutable laws of nature, in the room of the un- 
meaning subtleties of the schools, The sagacity 
and skill which Galileo displays in resolving the 
phenomena of motion into their constituent 
elements, and hence deriving the original principles 
involved in them, will ever assure to him a dis- 
tinguished place among those who have extended 
the domains of science. It is, perhaps, impossible, 
in the present advanced state of mechanical philo- 
sophy, to form a just estimate of the difficulties 
which then interposed towards a precise and 
luminous view of the fundamental principles of 
motion. It is universally admitted that those 
phenomena which come under the daily observa- 
tion of mankind, and which, on that account, do 
not possess any salient features on which the 
imagination can repose, are generally those which 
are most liable to elude the enquiries of ordinary 
minds. The principles which Galileo established 
by his sagacious researches had the effect of ele- 
vating mechanical science to the dignity of one 
of the most important subjects which can concern 
the attention of mankind. They were essential 
elements in the train of investigation which con- 
ducted Newton to the sublime discovery of 
Universal Gravitation ; and, in fact, they con- 
stitute the basis upon which the vast super- 
structure of the physico-mathematical sciences has 
been reared." (Introduction, p. n.) 1 

1 Montucla ("Histoire des Math&natiques," Paris, 1758, vol. ii. 
p. 191) says : " I dare to assert that if any one merits the name of 
precursor to Newton it is Galileo and not Descartes." See also 
Professor Jack's lecture on " Galileo and the Application of Mathe- 
matics to Physics," " Nature," vol xxi. pp. 40, 58. 




AFTER completing his " Dialogues on the Two 
New Sciences" (summer 1636), Galileo resumed 
his plan for determining longitudes by means 
of Jupiter's satellites, of which we have already 
said something in our Chapter VI I L The 
negotiations there described were resumed in 
1620, and after dragging on spasmodically were 
finally given up in 1632. Now (August 1636), 
hearing that the Dutch merchants had offered 
a prize of 30,000 scudi to the inventor of a 
sure method of taking longitudes at sea, Galileo 
offered his plan to the States-General, his 
friend Diodati of Paris being the go-between, 
as he wished to keep the matter from the 
knowledge of the Inquisition officials. 

As far back as 1612, Galileo had drawn 
up tables showing in advance the position of 
the satellites for several months, and these had 
been found to agree fairly well with subsequent 
observations of their actual positions. Since 
that time, amidst all his other employments, 

1636-1641] LONGITUDE METHOD 373 

he had for twenty-four years steadily continued 
his observations, with the object of bringing 
his tables to as high a state of accuracy as 
possible. This was the point to which the 
enquiries of the States, in accepting Galileo's 
offer, were chiefly directed. On nth November 
1636, the States appointed four Commissioners 
to communicate with him, and to report upon 
the various points on which they required in- 
formation. They voted him a golden chain as 
a mark of their respect, and assured him that 
in case his plan proved successful he should have 
no cause to complain of their generosity. A 
long correspondence ensued, in the course of 
which Galileo entered into minute details with 
regard to the devices by which he proposed 
to obviate the practical difficulties attending his 
method. 1 

After much delay, caused partly by the secret 
and roundabout way in which the corre- 
spondence had to be carried on, and partly by 
Galileo's gradual failure of sight, Hortensius, one 
of the commission, was deputed to set out for 
Italy, in July 1638, to confer with Galileo in 
person ; but the journey was put off at the last 
moment, as the following extract explains. We 
quote from a letter of Galileo to Diodati, dated 
1 4th August 1638 : 

"As ill-luck would have it, the Holy Office 

came to know of my negotiations with the 

States-General, which may do me great injury. 

I am, therefore, obliged to you for having induced 

1 See his letter to Lorenzo Realio, dated 6th June 1637. 


Signor Hortensius to give up his intended 
journey, and thereby averted some calamity to 

Soon after this, the brothers Ebers, Dutch 
merchants trading in Florence, were com- 
missioned to deliver the golden chain and a 
letter from the States. On arriving at the 
house in Via della Costa where Galileo was 
staying (as will presently be explained), they 
found the old man in bed, ailing, and totally 
blind! He asked them to read the letter aloud, 
and to give him the box containing the chain. 
Taking it in his hands, he in a few measured 
words expressed his thanks to them for their 
courtesy, and to the States for the signal mark 
of honour they had shown him. The box and 
the letter he would keep, but the chain he 
begged them to take back, as he did not think 
it proper to retain it, seeing that, owing to his 
blindness and increasing infirmities, the negotia- 
tions must be postponed. Seeing, however, in 
the action of the States- General a proof of 
their desire to adopt his method, Galileo re- 
solved to place all the papers containing his 
observations and calculations in the hands of 
Father Renieri, a former pupil and then professor 
of mathematics at Pisa, who was to finish and 
revise them, and then forward them to Holland. 
Before this was done a new delay was occasioned 
by the deaths in quick succession of every one 
of the four commissioners, Hortensius, the last, 
dying in April 1639. For two or three years 
the negotiations were entirely interrupted, and 


were then renewed by Constantine Huygens, 
but very ,soon after, Galileo himself died, and 
again the business was interrupted. To complete 
the singular series of misfortunes by which the 
trial of this method was impeded, just as Renieri, 
by order of the Grand Duke of Tuscany, was 
about to publish the Ephemerides, he also was 
attacked with a mortal malady, and after his 
death the MSS. were nowhere to be found! 
For two hundred years they were supposed to 
be lost, but sixty years ago they were discovered 
amongst the Galilean Papers by Alberi, and 
may now be consulted in the fifth volume of 
his edition of Galileo's Works. 1 

Just before his sight began to fail, Galileo 
made his last astronomical discovery, which is 
now known as the moon's libration. A remark- 
able circumstance connected with the moon's 
motion is that the same hemisphere is always 
visible from the earth, showing that she turns 
once on her axis in exactly the time of her 
monthly revolution round the earth. Now, 
Galileo who, if we may say so, was quite at 
home in the moon, and was familiar with the 
whole of her visible surface, observed that small 
fringes of her other side come alternately into 
view and again recede, according to her position 
in the heavens. 

This discovery was announced in a letter 

1 Renieri died in November 1647, when the longitude papers are 
supposed to have been stolen by one Giuseppe Agostini ; but see 
Favard's doubts on this subject' in his "Documenti Inediti per la 
Storia dei MSS. Galiletani," Rome, 1886, pp. 8-14. 


of 7th November 1637, to Micanzio, Venice, as 
follows : l 

"I see that you suppose I have not given up 
speculating. It is true I do go on speculating, but 
to the great prejudice of my health ; for thinking, 
joined to various other molestations, destroys my 
sleep and increases the melancholy of my nights ; 
while the pleasure which I have taken hitherto in 
making observations on new phenomena is almost 
entirely gone. 

" I have observed a most marvellous appearance 
on the surface of the moon. Though she has been 
looked at such millions of times by such millions 
of men, I do not find that any have observed 
the slightest alteration in her surface ; but that 
exactly the same side has always been supposed 
to be presented to our eyes. Now I find that 
such is not the case, but that she changes her 
aspect, as one who, having his full face turned 
towards us, should move it sideways, first to the 
right and then to the left ; or should raise or then 
lower it ; or, lastly, should incline it first to the right 
shoulder then to the left. All these changes I see in 
the moon ; and the large anciently-known spots which 
are seen on her face will help to make evident 
the truth of what I say. Add to these a further 
marvel, which is that these three mutations have 
their several periods the first daily, the second 
monthly, the third yearly. Now what connection 
does your Reverence think these three lunar periods 
may have with the daily, monthly, and yearly move- 
ments of the sea ? which by the common consent of 
all philosophers are ruled over by the moon." 2 

Galileo was not long in detecting one of the 

1 See also his letter to Alfonso Antonini with the significant 
address "Dalla mio carcere di Arcetri, li 20 Febbraio 1637" (ab 
incarnatione 1638). 

2 Compare pp. 171 and 259 on this subject of the tides. 

i6 4 i] MOON'S ITERATIONS 377 

causes of this apparent libratory or rocking move- 
ment. The diurnal or parallactic libration he saw 
was occasioned by our distance as spectators from 
the centre of the earth, which is also the centre 
of the moon's revolution. In consequence of 
this, as the moon rises we get an additional 
view of the lower part and lose sight of the 
extra portion of the upper part which was visible 
while we were looking down upon her when 
low in the horizon. The causes of the other 
motions noticed by Galileo are not so easily ex- 
plained without a reference to mathematics. Nor 
is it certain that Galileo himself understood them ; 
his conjecture of a connection with the tides is 
certainly wide of the mark. 

The moon in revolving round the earth spins 
once on her axis in the time occupied by a revolu- 
tion ; so turning, as is well known, the same side 
always towards the earth's centre. But this familiar 
truth is only approximate. The speed of rotation 
is uniform ; but the speed of motion in the orbit is 
not so, because that orbit is riot a circle but more 
truly an ellipse, in which (as is always the case 
with elliptic motion) the moving body travels faster 
while near the centre of attraction than when farther 
away. The result is that we see alternately a little 
round the eastern edge, and a fortnight later a little 
round the western. Combined with this libration in 
longitude is a libration in latitude due to the fact 
that the moon's axis of rotation is not exactly per- 
pendicular to the plane of its orbital motion, leaning 
a little towards us at one time, and a little away 
from us at the end of a fortnight. This enables us 


to see at times a few hundred miles beyond the 
North Pole, and at other times a similar extent 
beyond the South Pole. 

These two librations, though (as explained) due 
to independent causes, have approximately the same 
period about one month. Their effects, however, 
vary according to the changing position of the earth 
in its orbit; and any particular phase of the 
libration is more nearly reproduced after twelve 
months than after one. Galileo was, there- 
fore, justified in suggesting an annual period, 
although it is not customary at the present day 
to associate the annual period with any very 
distinct libration. 

The complaint in his eyes, which began to be 
troublesome towards the middle of 1636, steadily 
grew worse for some months. By the end of June 
1637, the sight of the right eye was gone, and that 
of the other was dimmed by a constant discharge. 
" I have been in bed for five weeks," he wrote to 
Diodati on 4th July, "oppressed with weakness 'and 
other infirmities from which my age (seventy-four 
years) forbids me to hope for release. Added to this 
(proh dolor ! ) the sight of my right eye that eye 
whose labours (I dare to say it) have had such 
glorious results, is lost for ever. That of the left 
'which was and is imperfect is rendered null by a coil- 
tinual running." But in spite of this affliction and 
his other sufferings (moral and physical) his interest 
in all things scientific was still unflagging. We find 
him carrying on an extensive correspondence with 
learned men in Germany, France, and Italy; con- 
tinuing the negotiations with the States-General 


about his longitude method; and filling up his 
leisure with astronomy and physics. 

Early in December 1637 Galileo became totally 
blind. "The noblest eye is darkened," wrote 
Castelli, "which nature ever made an eye so 
privileged and so gifted with rare qualities that it 
may with truth be said to have seen more than the 
eyes of all who are gone, and to have opened the 
eyes of all who are to come." His patience and 
resignation under this terrible calamity are truly 
wonderful ; and if occasionally a word of complaint 
escapes him it is in the chastened tone of the 
following words, written to Diodati on 2nd January 
1638 : 

" Alas ! revered Sir, Galileo, your devoted friend 
and servant, has been for a month totally and 
incurably blind, so that this heaven, this earth, this 
universe, which, by my remarkable observations and 
clear demonstrations, I have, enlarged a hundred, 
nay, a thousandfold bey'ond the limits universally 
accepted by the learned men of all previous ages, 
are now shrivelled up for me into that narrow 
compass which is occupied by my own person. " 

Hopes were entertained for a time that the 
blindness was occasioned by cataracts, and that he 
might hope for some relief from the operation of 
couching; but it soon became manifest that the 
disorder was not in the humours of the eye, but in a 
cloudiness of the cornea, which all remedies failed to 

Ever since his return to Arcetri from Siena, 
Galileo's friends in Rome lost no opportunity of 
interceding for him with the Pope, with a view to 


his complete liberty from the galling restraints of 
the Holy Office. Besides the ever faithful Castelli 
and Niccolini, M, de Peiresc and Comte de Noailles, 
as we have seen (p. 345), took up his case in the 
warmest manner, and several times either them- 
selves, or through the Pope's relatives, brought the 
matter before his Holiness in an urgent way. 
"They endeavoured/' wrote Galileo to Micanzio on 
I2th July 1636, "to convince his Holiness that I 
never had such an iniquitous thought as to make 
game of him, as my wretched enemies had per- 
suaded him, which was the prime motor of all my 
troubles. At length, the Holy Father pronounced 
my exculpation saying : c We believe it, we believe it 
now/ but he added, all the same, that the reading of 
my Dialogues was most pernicious to Christianity." 

In these negotiations the Cardinals Antonio 
and Francesco Barberini nobly seconded the efforts 
of Galileo's other friends. Indeed, if the Pope had 
meant more than fair speeches, there can be little 
doubt that the whole Congregation of Cardinals 
would have been ready to agree to Galileo's entire 
liberation another proof, if one be wanted, of the 
vindictiveness of Urban personally, 

At the end of September 1636, Galileo was 
allowed to visit the Grand Duke at his Villa 
Mezaomonte, outside Florence, going from Arcetri 
in a closed carriage in the early morning and 
returning late at night, so that he should not be 
seen on the way. Again, on i6th October, in the 
same year, he was allowed to go to Poggibonsi l to 

1 Poggibonsi was the meeting-place of another famous Florentine 
with another famous Frenchman. It was there, in June 1495, 

i6 4 i] HARSH TREATMENT 381 

meet the Comte de Noailles on his way back to 
France. This was the extent of the Papal 
clemency for many months. 

But now, on hearing of his blindness and many 
infirmities, the Pope seemed to have relented a 
little his savage treatment of the poor old man. 
Father Castelli was given to understand that a 
suitable petition would now be entertained, and 
on Qth January 1638, he sent a draft one which 
Galileo was to copy and return, with a medical 
certificate, direct to the Assessor of the Holy Office 
in Rome. This was done at once, but it was not 
enough. The local Inquisitor in Florence was 
instructed to see Galileo and make an exact report 
as to his health, and as to the likelihood, if he 
lived in Florence, of his promoting or encourag- 
ing there the propagation of his errors. The 
Inquisitor, Father Fanano, reported as follows, 
on 1 3th February 1638, to Cardinal Francesco 
Barberini : 

" In order the better to execute his Holiness's 
commands I went myself, accompanied by a strange 
physician, to see Galileo quite unexpectedly. My 
idea was not so much to put myself in a position to 
report on the nature of his ailments as to gain an 
insight into the studies and occupations he is 
carrying on, that I might be able to judge 
whether he was in a condition, if he returned to 
Florence, to propagate the condemned doctrine 
of the double motion of the earth. I found him 
entirely blind. He hopes for a cure, as the cataract 
only formed six months ago ; but at his age, of over 

Savonarola met King Charles VIII. of France on his skedaddle from 
Naples, and by prophetic denunciations kept him from looting 


seventy [74] the physician considers it incurable. 
He has besides a severe rupture, and suffers from 
continual weariness of life and sleeplessness which, 
as he asserts (and it is confirmed by the inmates of 
his house), does not permit him one hour's sound 
sleep in the twenty-four. He is besides so reduced 
that he looks more like a corpse than a living man. 
The villa is a long way from the city, and the 
access is inconvenient, so that he can but seldom 
and with much inconvenience and expense have 
medical aid. His studies are interrupted by his 
blindness, though he is read to sometimes ; and 
intercourse with him is not much sought, as in his 
poor state of health he can only complain of his 
sufferings and talk of his ailments to occasional 
visitors. I think, therefore, in consideration of 
this, if his Holiness in his boundless mercy should 
think him worthy and would allow him to live in 
Florence, he would have no opportunity of holding 
meetings, and if he had he is so prostrated that 
I think it would suffice (in order to make quite sure) 
to keep him in check by an-emphatic warning." 

This report at last seems to have softened the 
Papal heart, but only a little bit. A -partial relief 
was decided on at a sitting of the Congregation on 
26th February, under the presidency of the Pope, 
a full release to this man "more like a corpse/' 
appearing too dangerous to be ventured on ! On 
9th March, Galileo was allowed to enter Florence 
and occupy his son's little house, No. u Via 
della Costa, near the gate San Giorgio. Here 
the Inquisitor called and informed him, "for his 
advantage/' of the orders of the Holy Office not 
to go out in the city, under pain of actual imprison- 
ment for life and excommunication; not to speak 

1641] MAKES HIS WILL 383 

with any one whomsoever of the condemned 
doctrines ; and not to receive any suspicious 
visitors. It is characteristic of the ways of the 
Inquisition that Fanano set Galileo's own son to 
watch over his movements. The Inquisitor 
enjoined upon Vincenzio to see that his orders 
were obeyed, and, especially, to see that his 
father's visitors did not stay too long. In his 
report to Rome of loth March he remarks that 
Vincenzio can be trusted, "for he is greatly 
obliged for the favour granted to his father to be 
medically treated in Florence, and fears that the 
least offence might entail the loss of it. Besides, 
it is very much to his own interest that his father 
should behave properly, and keep up as long as 
possible, for with his death a 1000 scudi will go, 
which the Grand Duke allows him annually." 

Galileo's confinement in Florence was so 
rigorous that at Easter a special permission from 
Rome was required to go to the little Church of 
San Giorgio, one hundred yards down his street, to 
perform his Easter devotions, and even this per- 
mission only extended to Thursday, Good Friday, 
Saturday, and Easter Sunday. On the other hand, 
it would seem that he was allowed during June, 
July, and August, to go to and fro between his 
house in Via della Costa and his villa at Arcetri. 

During the summer of 1638, Galileo gradually 
sank so low that he and every one about him 
thought that his last hour was approaching. In 
this belief he dictated his will on 2ist August, and 
directed that he should be buried in the family 
vault of the Galilei in the Church of Santa Croce, 


Florence. To his daughter -Sister Arcangela (who 
survived him seventeen years) he left an annuity of 
25 crowns; to his nephews Vincenzio, Alberto, 
and Cosimo Galilei, 1 he bequeathed 1000 crowns, 
which, however, he revoked in a codicil added a 
few months later (igth November). He willed 
that any of his descendants who might enter a 
religious Order were to be by such act deprived of 
the enjoyment of any of his property that might 
come to them. His son Vincenzio was to have the 
rest, and, in the event of his death during the 
minority of his three children, their mother Sestilia, 
ne Bocchineri, was to be guardian jointly with his 
faithful disciple Mario Guiducci. 

Early in September the Grand Duke paid his 
sick Philosopher and Mathematician a visit of two 
hours' duration, and helped to prepare his medicines. 
These kindly visits were repeated more than once 
either by the Sovereign himself, who used to say, 
" I do so because I have only one Galileo/' or by 
some member of the Medici family. 2 

1 At this time Alberto, "il Grazioso Albertino," as Maria Celeste 
always called him, was staying with his uncle on a long visit Of 
Michelangelo's large family but three sons now remained, Vincenzio, 
who was teacher of music and singing to some Polish prince, Alberto, 
lute and violin player in the service of the Duke of Bavaria, and a 
younger boy, Cosimo, whom Alberto was maintaining. The wife, 
a son, and three daughters, all are supposed to have perished in the 
sack and burning of Munich a few years before (1634), 

2 These visits are recorded on a white marble slab over the entrance 
door as follows : 

Qui ove abito Galileo 

Non sdegn6 Piegarsi alia Potenza del Genio 
La Maesta di Ferdinando II. 

Dei Medici 

In the little garden at the back of the house is an old sundial, said to 
be the work of Galileo. 


f * ' " 

V,' / ,4, /-,//, ,/C" // 7 "/ '' ^"V" " tfUtt 

\\ .tfvwfyw M/f/ f > ,/ttm/f ilt . /, l( > '* >}t fa Mm ' f ft </> htwrt/. >b Jwwfr ,t't,t,'tt\ ,/'/i',f 

' , *v v /y .a '**, ^ tf. ,- j s * * ' '-v* ' f ~~ i " ' ' /P '" ' " 

Portrait of Galileo, aged about 75. 

[TV face J, 384- 

i6 4 i] THOUGHT TO BE DYING 383 

It had been for a long time Galileo's wish to 
have with him in the evening of his life his 
favourite disciple and lifelong friend Father 
Castelli, and as it was now supposed that his 
days were few, the Grand Duke sent the following 
instructions to his Ambassador in Rome, in a 
despatch from Cioli, on gth September 1638 : 

" Signor Galileo, from his great age and the 
illnesses which afflict him, is in a condition soon 
to go to the other world ; and although in this 
the eternal memory of his fame is already 
secured, yet his Highness is greatly desirous 
that the world should sustain as little loss as 
possible by his death, and that his labours may 
not perish, but, for the public good, may be 
brought to that perfection which he will not 
now be able to give them. He has in his 
thoughts many things worthy of him which he 
cannot be prevailed on to communicate to any 
but Father Benedetto Castelli in whom he has 
entire confidence. His Highness wishes, there- 
fore, that you should see Castelli, and induce 
him to procure leave to come to Florence for 
a few months for this purpose, which his 
Highness has very much at heart And if he 
obtains permission, as his Highness hopes, you 
will furnish him with money and everything he 
may require for his journey." 

Niccolini replied that Castelli had been himself 
to the Pope with this object ; that his Holiness, 
suspecting his design was to see Galileo, taxed him 
with it ; and upon Castelli stating that certainly he 
could not go to Florence without attempting to see 
him, he received permission to visit him, but only 
in the company of an officer of the Inquisition. 

2 B 


Early in October Castelli reached Florence, and 
was at once permitted to visit his old master, 
but was expressly prohibited under pain of ex- 
communication to converse with him on the 
condemned doctrines. Finding, as he did very 
soon, that the local officials of the Holy Office 
were inclined to curtail his interviews with 
Galileo, Castelli wrote repeatedly to Rome to 
obtain greater liberty. He protests in these 
letters that he would rather lose his life than 
converse on subjects forbidden by the Church, 
and gives as a reason for more frequent inter- 
views that he had received from the Grand 
Duke the twofold charge, to minister to Galileo 
in spiritual matters, and to inform himself fully 
about the Ephemerides of the Medicean Stars, 
which Giovan. Carlo de Medici, Lord High 
Admiral, wished to take with him to Spain. 
Early in November, the necessary permission 
arrived, "in consideration of these circumstances, 
and under the known conditions/' 

In January 1639 Galileo's general health was 
said to have so far improved as to permit of 
his returning to Arcetri, which he was never 
to leave again till death. Was this move a 
voluntary one? it may be doubted. In the first 
place, it is difficult to reconcile a voluntary return 
to his villa with his previous efforts to obtain 
permission to live in Florence. Then, there 
are many of his letters which bear the expressive 
addresses "Rusculo meo" (i7th August 1634), 
"Mio Carcere di Arcetri" (4th and i5th March 
1635, 9th February 1636, 4th March 1637, and 


20th February 1638), and " Dalla Villa Arcetri, 
Mio continuato Carcerede Esilio" (2Oth January 
1641). From such considerations it is allowable 
to conclude that Galileo would have little pleasure 
in going back to his "prison," and, therefore, 
that his banishment from the city was not 
voluntary, but the result of orders from 
Rome. 1 

Some time after his return to Arcetri, Galileo 
would appear to have solicited some favour 
from Rome which was inexorably refused. After 
this he came no more into direct contact with 
the Roman authorities, as he now gave up all 
hope of any amelioration of his lot from the 
implacable Pope. "As it pleases God, so also it 
should please us," was the refrain of many of his 
letters. Father Castelli also had by this time 
come to the conclusion that nothing more could 
be done for his unfortunate master, for hence- 
forth we find nothing in his letters but scientific 
disquisitions and spiritual consolations. 

The rest of Galileo's life was spent at 
Arcetri, where indeed, even if granted full 
liberty, his age and infirmities would probably 
have detained him a prisoner. The rigid manner 
in which the Holy Office had hitherto shadowed 

1 The Pope was kept fully informed of Galileo's doings by the 
local Inquisitor, and, doubtless, the publication of his Dialogues " in 
a heretical country," his negotiations about the longitude, "with 
heretical Hollanders," and the rumoured offer of a professorship 
in the "heretical" Athenaeum in Amsterdam, were not pleasing 
indications for his Holiness. The idea, at his advanced age and 
with shattered health, of retiring to Holland shows how much 
Galileo must have felt the restraints imposed upon him in his own 


him was now relaxed, and he was generally per- 
mitted to see the friends who came to express 
their respect and sympathy. The Grand Duke, as 
we have seen, or some member of his family, visited 
him frequently, and many distinguished strangers, 
such as Gassendi and Diodati of Paris, came 
into Italy solely for the purpose of testifying 
their admiration of his genius. Amongst the 
names of other Oltramontani is that of a young 
Englishman, who was able to give him the 
gratifying information that his Dialogues of 
1632 were being eagerly read by the learned 
men in England. This was John Milton, then in 
his twenty-ninth year, and already known as a poet 
of great promise. Milton left England for the 
Continent some time in April 1638, and reached 
Paris early in May ; thence travelling by way 
of Nice, Genoa, Leghorn, and Pisa, he arrived 
in Florence early in August Masson, in his 
" Life of Milton," has collected what little we 
know of this visit. The young poet was en- 
thusiastically received by the members of the 
Accademia della Crusca, and assisted at many 
of their reunions. " In the private academies 
of Italy," he says, "whither I was favoured to 
resort, some trifles which I had in memory, 
composed at under twenty or thereabouts, met 
with acceptance above what was looked for; and 
other things, which I had shifted, in scarcity of 
books and conveniences, to patch up amongst 
them, were received with written encomiums 
which the Italian is not forward to bestow on 
men of this side the Alps." 


The only specific reference by Milton to his 
visits to Galileo occurs in the following passage 
in the " Areopagitica," a discourse addressed to 
the .Lords and Commons against the proposed 
licensing of printed books : 

" I could recount what I have seen and 
heard in other countries, where this kind of 
Inquisition tyrannizes, when I have sat among 
their learned men (for that honour I had) and 
been counted happy to be born in such a place 
of philosophic freedom, as they supposed England 
was, while themselves did nothing but bemoan 
the servile condition into which learning amongst 
them was brought; that this was it which had 
so dampt the glory of Italian wits, that nothing 
had been written there now these many years 
but flattery and fustian. There it was that I 
found and visited the famous Galileo, grown old, 
a prisoner to the Inquisition for thinking in 
astronomy otherwise than the Franciscan and 
Dominican licensers thought/' 

Milton is said to have first met Galileo some 
time in September 1638, in which case the meeting 
probably took place in the little house in Via della 
Costa. The poet left Florence, via Siena, early 
in October, for Rome, where he spent the winter, 
paying a short visit to Naples. Early in March 
1639, he returned to Florence, where, according 
to his own account, he was received with no less 
eagerness than if the return had been to his native 
country and friends at home. On this occasion he 
stayed two months, and Masson believes that he 
saw Galileo again and, probably, more than once. 


These meetings would certainly have taken place 
at the villa in Arcetri. 

" There unseen 

In manly beauty Milton stood before him 

Gazing with reverent awe Milton his guest. 

Just come forth, all life and enterprise ; 

He in his old age and extremity, 

Blind, at noonday exploring with his staff ; 

His eyes upturned as to the golden sun, 

His eyeballs idly rolling. Little then 

Did Galileo think whom he received ; 

That in his hand he held the hand of one 

Who could requite him who would spread his name 

O'er lands and seas great as himself, nay, greater ; 

Milton as little that in him he saw, 

As in a glass, what he himself should be, 

Destined so soon to fall on evil days 

And evil tongues so soon alas, to live 

In darkness, and with dangers compassed round, 

And solitude." l 

Another great Englishman, Thomas Hobbes 
of Malmsbury, during his travels abroad, 1634-37, 
spent some time in Florence, circa 1635-6, and 
often met his brother philosopher for whom he con- 
ceived and ever retained the warmest admiration. 2 

The French philosopher Descartes was, prob- 
ably, the only great man who, finding himself in 
Florence, did not honour himself by calling on 
Galileo. Arago tells us that during his wanderings 
Descartes visited parts of Italy and returned to 
France (1625), passing through the capital of 
Tuscany. He adds "One would be astonished 
to learn that he had no wish to be presented to 

1 Rogers' Italy (the Campagna of Florence). The meeting of 
Milton and Galileo is the subject of a long poem by Giacomo Zanella. 
"Versi," Florence, 1868. 

2 See Galileo's letter to Micanzio, dated ist December 1635. 


Galileo, did we not know that by an inexplicable 
aberration he was always indifferent to the works 
and admirable discoveries of the Italian philo- 
sopher." l In the same way, during his previous 
peregrinations in Germany, as a soldier of fortune, 
Descartes would not see Kepler, although he called 
him his master in optics. 

During the summer of 1639 Vincenzio Viviani, 
then eighteen years old, came to live with Galileo and 
remained with him to the end, glorying in the title 
of " ultimo suo discepolo." Almost from the first day 
a strong attachment sprang up between the two, 
the old master conceiving a fatherly affection for 
the talented youth, and the pupil, a love and venera- 
tion for the master which he preserved through 
life. In his old age when in his turn he had 
acquired a claim to the reverence of another genera- 
tion, our Royal Society, in electing him a member 
(1696), appear to have felt that the complimentary 
language in which they addressed him as the first 
mathematician of the age would be incomplete 
without an allusion to the friendship that gained 
him the cherished title of "the last disciple of 

Early in 1640, the peripatetic Professor in 
Padua, Fortunio Liceti, published a book on the 
phosphorescence of the Bologna Stone, so called 
from its discovery in 1602 by Casiorolo, a shoe- 
maker and alchemist of Bologna. In his fiftieth 
chapter he treats of the faint light of that part of 

1 He used to say that he saw nothing in the writings of Galileo to 
make him envious, and hardly anything which he would care to call 
his awn. See Martin's " GalUeV' pp, 290 and 311. 


the new moon not directly illuminated by the sun, 
holding that the moon was phosphorescent like the 
Bologna Stone, and rejecting Galileo's explanation 
that it arises from a reflection of the sun's rays 
from our earth to the moon and their re-reflection 
from the moon back to us. Galileo was undecided 
whether it were not best to take no notice of 
Liceti's objections, when a letter from Leopoldo 
de Medici, brother of the reigning Grand Duke, 
relieved him of his doubts. This prince, who some 
years later gained a permanent place in the history 
of science by founding the celebrated Accademia 
del Cimento, solicited Galileo's views on Liceti's 
arguments, This challenge sufficed to rouse all 
his dialectic skill, and he dictated a reply (i3th 
March 1640) in the form of a letter to Prince 
Leopoldo, which in spirit and crushing argument, 
is quite equal to the best controversial work of 
his manhood. An extract will serve to show the 
difficulties of this composition. 

" I am obliged to have recourse to other hands 
and other pens than mine since my sad loss of 
sight. This of course occasions great loss of time, 
particularly now that my memory is impaired by 
advanced age, so that on placing my thoughts on 
paper, many and many a time I must have the 
foregoing sentences read to me before I can tell 
what ought to follow; else I should repeat the 
same thing over and over again. Your Highness 
may take my word for it that between using one's 
own eyes and hands and those of others there is 
as great a difference as between playing chess with 
one's eyes open and blindfolded." 

This letter of fifty (printed) pages led to a 


correspondence with Liceti, covering the period 
from June 1640 to January 1641. The letters are 
full of science and philosophy, and are pervaded by 
a verve, an urbanity, and a piquant irony, which 
make them refreshing reading even to-day. In 
them he not only deals with the arguments and 
pretensions of his adversary, but he delivers his 
opinions very freely on the whole method of Aris- 
totle and of the modern peripatetic school of his 
debased followers. The correspondence ended in 
Galileo sending a revised copy of his letter to 
Prince Leopoldo to Liceti, which the latter printed 
in 1642 together with his reply. 

Ten months before his death, a last occasion of 
discussing the Copernican theory was in a manner 
forced upon Galileo. The mathematician Pieroni 
having announced the discovery of a small annual 
parallax for some of the fixed stars (which, if true, 
would place the correctness of the Copernican 
theory beyond all question), Francesco Rinuccini, 
a former pupil, communicated this intelligence to 
his old master on 23rd March 1641, and at the 
same time begged his opinion on a recently 
published argument against the revolution of the 
earth, namely, since we see exactly one-half of 
the firmament, it must follow that the earth is 
in the centre of the starry sphere. This was the 
impulse to Galileo's reply of six days later (2 9th 
March), which, as Martin and Von Gebler say, 
whether a jest or a mask, should never have been 
written. He begins by saying that the falsity of 
the Copernican doctrine can in no way be doubted, 
especially by Catholics, since we have opposed to 


it the irrefragable authority of Holy Scripture, as 
interpreted by the greatest masters of theology, 
whose unanimous declaration makes the stability of 
the earth in the centre, and the mobility of the 
sun around it, a certainty. This so resembles the 
ironical style of his letter of 1618 to Prince 
Leopold of Austria when forwarding his treatise 
on the tides, the introduction to his Reply to 
Ingoli in 1624, and his preface to the discreet 
reader in his Dialogues of 1632, that it cannot be 
taken as seriously meant He then goes on, as at 
the end of the Dialogues just mentioned : 

"The grounds on which Copernicus and his 
followers have maintained the contrary fall to 
pieces before the fundamental argument of the 
Divine Omnipotence. For, since this is able to 
effect by many, aye, by endless means what, so far 
as we can see, appears practicable in one way only, 
we must not limit the power of God, and persist 
obstinately in our mistaken notions. As I hold the 
Copernican theory to be insufficient, so, that of 
Ptolemy, Aristotle, and their followers, appears to 
me far more delusive and mistaken, because its 
falsity can be clearly proved without going beyond 
the limits of human knowledge." 

The Copernican theory being thus condemned, 
and the alternatives, those of Ptolemy and Tycho 
Brah6 being demonstrably untenable, it only remains, 
he says, for philosophers to find some other system 
of which both science and theology can approve. 
Then coming to the new argument against the 
mobility of the earth which so troubled his corre- 
spondent, he shows that it is a mere petitio principii, 


and has not the least foundation in astronomical 
science ; and, finally, as to the reported discovery 
of a stellar parallax, he says briefly that if Pieroni's 
observation be correct, human reason would compel 
us to conclude that the earth is not immobile 
in the centre of the starry sphere. But, as if 
repenting his audacity in saying this, he hastens 
to add, "If Pieroni may be mistaken in supposing 
that he had observed a parallax of a few seconds, 
those others may be still more mistaken who assert 
that the visible firmament never varies, not even 
one or two seconds, for such an exact observation 
is utterly impossible, partly from the insufficiency 
of astronomical instruments, and partly from the 
refraction of light/' 

Cesare Cantu and some writers after him have 
assumed from this letter that at the close of his 
life Galileo had really renounced, and from pure 
conviction, the astronomical doctrines for which he 
had laboured and suffered for thirty years. But if 
we bear in mind all the circumstances under which 
the letter was written, we will see that this assump- 
tion is quite untenable, and that we must conclude 
with Martin and Von Gebler that the passages on 
which Cantii and his followers rely were not meant 
to be taken an pied de la lettre that they were, as 
Martin puts it, " la protestation habilement ironique 
d'une pens^e contrainte L se cacher." * 

A few months before his mortal illness Galileo 
once more gave evidence of his genius. It has 
been remarked in the progress of science and 

1 Martin's " Galilee," p. 235 ; Getter's " Galileo and the Roman 
Curia," p. 305. 

396 GALILEO AT ARCETRI [1636-1641 

scientific invention that the steps, which on looking 
back seem the easiest to make, are often those 
which are the longest delayed. The application of 
the pendulum to clocks is an instance of this. We 
have seen that Galileo was early convinced of the 
value of the pendulum as a measurer of time, 
and that as far back as 1582 he used it in 
the pulsilogia; yet fifty-five years later, although 
constantly using it meanwhile, he had not de- 
vised a more practicable application of it than 
that described in his "Astronomical Operations/' 


" I make use of a heavy and solid pendulum of 
brass or copper, in the shape of a sector of twelve 
or fifteen degrees, the radius of which may be two 
or three palms (the greater it is the less trouble in 
attending it). This sector I make thickest in the 
middle radius, tapering gradually towards the edges, 
where I terminate it in a tolerably sharp line, to 
obviate as much as possible the resistance of the 
air, which is the sole cause of its retardation. This 
sector is pierced in the centre, through which is 
passed an iron bar shaped like those on which 
steelyards hang, terminated below in an angle, and 
placed on two bronze supports. If the sector (when 
accurately balanced) be removed several degrees 
from the perpendicular, it will continue a to-and-fro 
motion through a very great number of vibra- 
tions before coming to rest ; and in order that 
it may continue its oscillations as long as it is 
wanted, the attendant must occasionally give it 
a smart push so as to carry it back to large 

" Now to save the fatigue of continually counting 
the oscillations, this is a convenient contrivance a 
small delicate needle extends from the middle of the 


From Favaro's " Galileo e Cristiano Huygens. Nuovi document! 
sull' applicazione del pendolo all' orologio" (Nuovi studi 
Galileiam] Venice, 1891). 


sector which in passing strikes a rod hung at one 
end. The lower end of this rod rests on the teeth 
of a horizontal wheel as light as paper. The teeth 
are cut like those of a saw. The rod striking 
against the perpendicular side of a tooth moves it, 
but when returning it slips over the oblique side of 
the next tooth and falls at its foot, so that the 
motion of the wheel will be in one direction only. 
By counting the teeth you may see at will the 
number passed, and, consequently, the number of 
oscillations or periods of time which you wish to 
measure. You may also fit to the axis of the wheel 
a second, with a smaller number of teeth and in 
gear with a third wheel having a greater number of 
teeth, and so on. As the error of clocks consists 
chiefly in the inability of mechanicians to adjust 
what we call the balance of the clock so that 
it may vibrate regularly, my very simple pendulum, 
which is not liable to any alteration, affords a 
means of maintaining the measures of time always 

It was chiefly because of the inadequacy of this 
method that the negotiations with the States- 
General were finally broken off. Now, in the 
second half of 1641, it occurred to Galileo (as 
stated by Viviani who was present) that the prob- 
lem could be solved by adding the pendulum to 
the ordinary clock as a regulator of its movements. 
He explained his idea to his son, Vincenzio, who 
made a drawing (of which we reproduce a facsimile) 
from his father's dictation. Before the plan could be 
tried Galileo fell ill, and this time did not recover. 
The matter was laid aside, but seven years after his 
father s death, Vincenzio resumed it, and was engaged 
in constructing what would have been the first 


pendulum clock, when he too fell ill and died, i6th 
May I649. 1 

1 For more on this interesting subject, see Viviani's account which 
he wrote expressly, 2Oth August 1659, for Prince Leopoldo de Medici 
in Alberi's vol. 14. The application of the pendulum to clocks has 
been claimed for the Swiss, Burgi, and for Richard Harris of London 
in 1611 ; but Christian Huygens appears to have been the first to 
actually construct a pendulum clock between 1654 and 1657. 



THE last few months of Galileo's life were soothed 
by the devotion of his friends, and the homage 
of all to whom his name was known. The Grand 
Duke was most attentive in enquiries after his 
health, and sent him supplies of his choicest 
wines and other delicacies. Besides the creature 
comforts thus supplied, Galileo had the pleasure of 
once more meeting his old friend Castelli, and dis- 
coursing with him on the things of that world to 
which they both were tending. The good Father 
arrived from Rome towards the end of September 
1641, intending to stay to the end, but he had to 
return to his duties early in November. 

Towards the middle of October, Evangelista 
Torricelli, then a rising philosopher of thirty-three, 
came to stay at the villa, and did not leave it until he 
followed the coffin of the great master. Torricelli first 
studied under Castelli, and, later on, occasionally lec- 
tured for him in Rome, in which manner he was em- 
ployed when Galileo, who had seen his early treatises 
on mechanics and on the motion of fluids, and had 
augured the greatest success from such beginnings, 


1642] LASTDAYS 401 

invited him to Arcetri. He succeeded the master 
in his appointment at the Court of Florence, but 
survived him only a few years, dying in 1647, at the 
early age of thirty-nine. The youthful Viviani, as 
we know, was already in the villa, acting as a loving 
son to an honoured father. He, Torricelli, and 
Vincenzio Galilei shared between them the duties 
of amanuensis and companion. 

On the ist October, Bonaventura Cavalieri, 
another of Castelli's distinguished pupils, whom 
Galileo used to call " another Archimedes," wrote 
from Bologna, expressing his grief at not being 
able, on account of his infirmities, to join the dis- 
tinguished company ; and another lifelong friend 
and champion, Fra Fulgenzio Micanzio of Venice, 
to whom Galileo had written in praise of his new 
collaborateur., replied on 2nd November in similar 
terms ; he envied, he said, the reunions of such an 
illustrious triumvirate, Galileo, Castelli, and Torri- 

On 5th November, Galileo was attacked by a 
low fever with pains in the limbs, which confined 
him to bed from which he never rose again. Yet 
in spite of these sufferings, aggravated by insomnia, 
and by frequent attacks of palpitations of the heart, 
his mind was clear and busy to the last, and in 
the intervals of pain he passed hours in scientific 
discussions with Torricelli and Viviani who care- 
fully noted his utterances. These related to the 
Mechanical Problems of Aristotle, to his long 
contemplated (since 1609) Treatise on the Move- 
ments of Animals, to the properties of the cycloid, 
but chiefly to the force of percussion. His notes 

2 c 


on the first three subjects have not come down 
to us, but those on percussion now form the 
sixth Dialogue added to the later editions of the 
u Dialogues on the Two New Sciences," as already 

On the evening of 8th January 1642, the year 
of Newton's birth, Galileo breathed his last, at the 
age of nearly seventy-eight, fortified by the last rites 
of the Church, and the benediction of Urban VIII. 
His son Vincenzio and his wife, Torricelli and 
Viviani, and the parish priest of Arcetri were 
around his bed. 

Not only was his power of making a will 
disputed, but the propriety of laying his body in 
consecrated ground was questioned by some 
fanatics, who could only see in the life of this 
great man the one fact, that he had died under 
sentence of the Holy Office, " vehemently sus- 
pected" of heresy. On a reference to the proper 
authorities, his power of making a will was upheld, 
and it was also ruled that his friends had full 
right to place his remains in consecrated ground. 

Accordingly, preparations were at once made 
for a public funeral such as might best show the 
sense of the Court and the city of the greatness 
of their loss, and the sum of 3000 crowns was 
quickly collected to cover the expense of a marble 
monument in the Church of Santa Croce. These 
and other particulars were reported to Rome, 
whereupon the Pope sent for the Tuscan Ambas- 
sador, Niccolini, and desired him to tell his 
master that it would be a bad example for the 
world if such honours were rendered to a man 


who had been arraigned before the Holy Office 
for false and erroneous opinions ; who had com- 
municated them to many others ; and, altogether, 
had caused the greatest scandal to all Christendom. 
Niccolini, reporting this interview on 25th January 
1642, advised that the project of a funeral oration 
and a monument be laid aside, at least for a time ; 
since, as his Holiness claimed to be absolute 
master of all churches and consecrated grounds, 
it was likely that an insistence on these public 
honours would draw on the Grand Duke himself 
some such affront as was offered, not long before, 
to the Duke of Mantua (by the removal of the 
body of the Countess Matilda from Mantua to St 
Peter's in Rome). 1 So determined and threatening 
was the Pope's attitude in this matter that the 
weak Ferdinando II. was not able to resist 
Proposals both for a public funeral and a 
monument were laid aside, and the friends of the 
great dead were constrained to hide away (there 
was not even an epitaph) his beloved remains in 
a little room or cell (9 feet by 6) to the right of 
the altar in the Chapel of the Novices, situated at 
the end of the corridor leading from the south 
transept of Santa Croce to the great sacristy. 2 
It was not till nearly thirty-two years later 
(September 1673) when Urban VIII. had long 

1 At the same time the Inquisitor in Florence was instructed to 
make similar representations to the Grand Duke ; and if without the 
desired effect, he was to see that there was nothing in the epitaph 
that could be construed as an insult to the Holy Office, and he was 
to exercise the same care in the preparation of the funeral oration. 

2 Here were also laid in 1703 the remains of Viviani who desired 
to lie beside his master. 

404 DEATH OF GALILEO [ X 6 4 2 

been dead, that Father Gabriele Pierozzi of Santa 
Croce ventured to honour the illustrious dead by 
painting on the wall of the cell a somewhat 
bombastic inscription, and placing on a plaster 
bracket above it a small bust of Galileo in clay, 
painted in imitation of marble. The bust was 
removed in 1737, at the translation of Galileo's 
remains (to be presently described), but the 
inscription remains, partly obliterated, and in a fair 
way of disappearing, by the scaling of the plaster. 1 

In 1693, Viviani ventured to erect the first 
public monument to Galileo. On the front of his 
house in Via dell' Amore (now Via San Antonino), 
he placed a bronze bust of the philosopher, which 
was cast from a mould of a terra-cotta bust made in 
1610 by Giovanni Caccini, the sculptor, by desire of 
Cosimo II. Over this and on both sides of the 
entrance door, on large marble scrolls, are 
engraved long eulogies of the master. 2 

But Viviani was not content with these pious 
memorials. Dying in 1703, he left his property 
to his nephew, the Abbe Jacopo Panzanini, 
charged with the condition of erecting a suitable 
monument in bronze and marble as soon as 
permission to do so could be obtained. For over 
thirty years no attempt was made to carry out his 
wishes, and then the business was taken in hand, 

1 Brewster ("Martyrs of Science ") gives a copy of this inscrip- 
tion, but not quite accurately. See Albert's "Opere di Galileo," 
vol. xv. p. 405, 

2 For these, see Alb&ri's vol. xv. pp. 373-80. Viviani had also 
caused a medal to be struck in honour of Galileo ; and no less than 
five other commemorative medals were issued during his residence 
in Padua and Florence. All of these are reproduced in Nelli's and 
Ventures works. 

Galileo's Monument in Santa Croce, Florence. 

[ To face /. 404, 


not by Viviani's heir, but by the executor Gio. 
Battista Nelli. In 1734, enquiries were made at 
Rome as to whether there was any decree of the 
Holy Office which would prevent the erection of 
a monument. The reply, i6th June 1734, was 
that there was nothing against such a proposal, 
provided the intended inscription were submitted 
for approval. The 'work was accordingly taken 
in hand, but dragged on slowly for nearly three 
years. Finally, on the night of i2th March 1737, 
and in presence of the leading clergy, of all 
the professors of the schools of Florence and Pisa, 
and of learned, literary, and artistic men from all 
parts of Italy, Galileo's remains were removed 
with great pomp to the mausoleum in the north 
aisle of Santa Croce the Pantheon of the 
Florentines whither also were conveyed the 
remains of Viviani, according to his last wishes. 

The monument, which we reproduce from a 
photograph, is the work of Gio. Battista Foggini, 
assisted by his son, Vincenzio, and Girolamo 
Ticciati, The bust of Galileo and the figure 
representing astronomy are the work of Vincenzio 
Foggini, while the figure of geometry is from the 
chisel of Ticciati. 

" In Santa Croce's holy precincts lie 
Ashes which make it holier, . . 

here repose 

Angelo's, Alfieri's bones, and his 
The starry Galileo, with his woes ; 
Here Machiavelli's earth returned to whence it rose." 
BYRON, Childe Harold, Canto IV. 54. 

Galileo's old resting-place was about two yards 


high, and consisted of rude masonry, built on the 
floor and against the wall of the cell. Viviani's 
was close beside it, of similar structure but smaller. 
On breaking away the stonework of the latter, 
which it was found convenient to remove first, 
and on opening the coffin, a lead plate was found, 
attached to the inside of the lid, on which was 

" Vincenzio Viviani Morto il di xxii Settembre 1703." 

The cover was then replaced, and the coffin was 
transferred to its new resting-place. 

Returning to the little chapel, the masonry of 
Galileo's tomb was removed, and the coffin laid 
open. Giovanni Targioni-Tozzetti, one of the pall- 
bearers, tells us that the face was well preserved, 
and like the bust by the sculptor Caccini, made in 
1610, and also very like Sustermans' portrait, 
circa 1635 (a copy of which forms the frontispiece 
of the present work). A heavy iron girdle was 
found in the coffin, so fashioned as to lead 
Targioni-Tozzetti to suppose that the wearer must 
have suffered from rupture on both sides. It was 
also observed that the body was pierced, probably 
to let escape an accumulation of water, and the 
opening was filled with coarse wadding. This 
seems to indicate dropsy, which must, therefore, 
be added to the poor old man's other maladies. 1 

During the work of exhumation and identifica- 
tion Canon Gio. Vin. Capponi, President of the 
Sacra Accademia Fiorentina, took an opportunity 

1 Targioni-Tozzetti: "Notizie degli Aggrandimenti delle Scienze 
Fisiche in Toscana," Florence, 1780. 


of removing with a knife the thumb and forefinger 
of Galileo's right hand! because, as he said to 
Targioni-Tozzetti, they held the pen with which 
so many fine things were written ; but the latter 
(who tells the story in the work just quoted) tapped 
the skull, and said he would rather have some of the 
brains which conceived the grand thoughts. These 
relics were still preserved in the Capponi family 
down to 1845, and are now apparently lost. 

Soon after, Anton. Francesco Gori, Professor of 
Ancient History in the University of Florence, 
removed the index finger of the left hand, which, 
at his death, passed to Canon Angelo Bandini. 
At his death in 1803, it came into the custody of 
the Laurenzian Library (of which Bandini had been 
Keeper), and in 1841 it was transferred to its 
present place in the Tribuna di Galileo in Florence. 
It is enclosed in a crystal urn, and bears an inscrip- 
tion from the pen of Tommaso Perelli, a celebrated 
astronomer of Pisa, circa 1770 

" Leipsana ne spernas digit! quo dextera coeli 
Mensa vias nunquam visos mortalibus orbes 
Monstravit, parvo fragilis molimine vitri 
Ausa prior facinus cui non Titania quondam 
Suffecit pubes congestis montibus altis 
Nequidquam superas conata ascendere in arces." 

At the same time, yet another idolater, Dr 
Antonio Cocchi, Professor of Natural Philosophy 
and Anatomy, took away the fifth lumbar vertebra, 
which, after passing through many hands, came 
into the possession of Dr Thiene, In 1823, he 
presented it to the University of Padua, where it 
is now preserved in the museum attached to the 
physical science laboratory. 

4 o8 CONCLUSION [1642 

From Viviani's biography of Galileo (1654) we 
learn that he was of a cheerful and pleasant counte- 
nance, especially in later life, square of frame, well- 
proportioned, and rather above the middle height 
His complexion was fair and sanguine, his eyes 
sparkling, and his hair and beard, of which he had 
an abundance, of a reddish hue. Up to the age 
of thirty his constitution was sound, but after his 
first serious illness in 1593 he was beset by various 
complaints, which increased in gravity and frequency 
as the years rolled on. Thus for nearly fifty years 
he was subject to frequent attacks of fever, 
hypochondria, and rheumatism, and, latterly, to 
gout, rupture, and insomnia. Yet, with such a 
multitude of complaints as would have made a 
miserable valetudinarian of any other man, his 
industry was extraordinary. It was said that no 
one had ever seen him idle, and one of his favourite 
sayings was that occupation is the best medicine for 
both mind and body. 

His temper was what we would call short ; he 
was easily ruffled, but more easily pacified a 
condition which, if not produced, was certainly 
aggravated by physical suffering, and the troubles 
of all kinds, public and private, from which for sixty 
years he was seldom free. 

In his younger days he was fond of a country 
residence. Besides believing that the city air 
was prejudicial to his health, he was wont to say 
that the city was in a manner a prison for the 
speculative philosopher; that in the country alone 
was the book of nature open to him whp cared to 
read and learn from it ; that the characters in which 


that book was written were those of geometry ; and 
that when once they were fully deciphered we might 
hope to penetrate the deepest mysteries of nature. 

Though he loved the quiet of a country life, he 
was fond of the society of friends, to whom he 
constantly dispensed a hospitality simple but 
hearty. Gardening in all its forms was his 
favourite and almost his only relaxation from the 
severe studies which filled his days, and great part 
of his nights. He was a connoisseur in wines, and 
was diligent in tending his own vineyard. He used 
to say that wine is a compound of humour and 
light ; and Viviani has preserved one of his recipes 
for wine of the best quality, that juice only should 
be taken which is pressed out by the mere weight 
of the heaped grapes of the ripest kind. 

All through life he was fond of wine, perhaps 
sometimes too fond for his health and temper, 1 and 
even in old age the taste was apparently as keen as 
ever, as the following curious letter will show. It 
is headed " From my prison at Arcetri," and is 
dated 4th March 1637 

" I am forced to avail myself of your assistance, 
agreeably to your obliging offers, in consequence 
of the excessive chill both of weather and of old 
age, and from having drained out my grand 
stock of a hundred bottles which I laid in two 
years ago not to mention some minor par- 
ticulars during the last two months which I 
received from my serene master, from the 
Cardinal de Medici, the princes, and the Duke 
of Guise; besides clearing out two barrels of 
the wine of this country. Now I beg that, with 

1 See Favaro's "Galileo e Suor Maria Celeste," p. 141. 

4 io CONCLUSION [1642 

all due diligence and industry and taking 
counsel with the most refined palates, you will 
provide me with two cases, ^.e. forty flasks of 
different wines, the most exquisite that you can 
find. Take no thought of expense, because I 
stint myself so much in all other pleasures that 
I can afford to lay out something at the shrine 
of Bacchus, without giving offence to his two 
companions Venus and Ceres. You must be 
careful to leave out neither Scillo nor Carino (I 
believe they should be called Scylla and 
Charybdis), nor the country of my master 
Archimedes of Syracuse, nor Greek wines, nor 
clarets, etc. The expense I shall easily be able 
to satisfy, but not the infinite obligation I shall 
owe you." 

In other expenditure Galileo observed a 
just mean between avarice and prodigality. He 
spared no cost necessary for the success of his 
many and various experiments, and spent large 
sums in charity, and in assisting those in whom 
he discovered promise of any kind, many of whom 
he entertained in his own house. Even in the 
last year of his life, he had one such poor scholar 
in the Villa, as may be seen from Cesare Monti's 
letter of 3Oth May 1640, and Galileo's reply of 
2nd November following. 

He seldom conversed on mathematical or 
philosophical topics, except with his intimate 
friends ; and when such subjects were abruptly 
brought before him by others, as was often 
done by the numerous strangers who called upon 
him, he showed great readiness in parrying 
and turning the conversation into other channels, 
in such manner, however, that he usually contrived 


to say something to satisfy the curiosity of the 
enquirer. His demeanour, therefore, was modest 
and unassuming. Of self-praise so much is re- 
corded of him that, when his sight was decaying 
beyond all hope of recovery, he used to comfort him- 
self by saying that of all the sons of Adam none 
had seen so much as he. He neither depreciated 
nor envied the talents of other men, but gave to 
each his due, according to his own lights. It 
was the custom of many of his followers to 
speak of Aristotle with contempt, not so the 
master, he would only say that the methods of 
reasoning of the great Stagirite philosopher 
appeared to him unsatisfactory, or erroneous ; 
and such of the works of Aristotle as he did 
admire, he admired frankly, especially those on 
Ethics and Rhetoric. He exalted Plato to the 
skies, calling his eloquence golden. Pythagoras, 
he thought, unequalled among philosophers ; but 
Archimedes was the only one of the ancients 
whom he called master. Much of Virgil, Ovid, 
Horace, and Seneca, he knew by heart. 

His memory was uncommonly tenacious, and 
was stored with a variety of old songs and 
stories which he would bring out on all suitable 
occasions The Sonnets of Petrarch, the Rime 
of Berni, and the heroic stanzas of the "Orlando 
Furioso" he could repeat in great part. As we 
have already seen in our Chapter II, his excessive 
admiration of Ariosto determined the side which 
he took against Tasso in the virulent controversy 
which had divided Italy so long on the merits 
of these two poets. It should, however, be 

4 i2 CONCLUSION [1642 

remembered that his matured taste receded from 
the violence of his youthful prejudices, and, 
towards the end of his life, he avoided as much 
as possible making any comparisons, and, when 
forced to give an opinion, he would say that 
Tasso's appeared the finer poem, but that 
Ariosto's gave him greater pleasure. 1 

Of his obiter dicta, not many have been 
preserved. Besides those already noted, one or 
two others may be quoted. The book of philo- 
sophy, he used to say, is the book of nature 
which lies always open before us, and is written 
in characters of geometry. Not to know, then, 
geometry, is to be ignorant of nature. Another 
favourite axiom, conveying the same truth, was 
Ignorato motu ignoratur natura. When the 
understanding has experience to inform it, reason 
is not indispensable, was another of his sayings. 
He was wont to say that he had never met 
with a man so ignorant that something might 
not be learnt from him ; again, that ignorance in 
others was his best teacher, for in learning how 
to combat ignorance he taught himself. He used 
to say that it was the privilege of the sad and 
miserable not to be envied by the merry, and 
of the wicked, not to be envied by the good. 

As a teacher he was no less loved and 
valued than as a friend. However clear a subject 
might be to his own mind, he was not satisfied 
till he made it as clear to the minds of his pupils. 
"From Signor Galileo/' wrote Marsili (in 1637), 

1 See his letters of 5th November 1639 and igth May 1640, to 
Francesco Rinuccini. 


" I learnt more in three months than I did in 
as many years from other men." " I thank 
God," said Paolo Aproino, "for having given 
me for master the greatest man the world has 
ever seen." "When/ 1 wrote Ciampoli, after 
his retirement in disgrace to Montalto in 1633, 
"When shall I embrace you as a father and 
listen to you as an oracle ? " Viviani and Gherar- 
dini are equally enthusiastic ; and even some of his 
stoutest adversaries, as Lagalla and Grassi, readily 
admitted his greatness in this respect. 

Pages might be filled with expressions of 
gratitude and devotion such as these culled 
from the letters of Galileo's disciples. And truly 
the master himself might adjudge them to be 
of higher value, as a testimony to his greatness, 
than the marble monument under which he now 
reposes in the Church of Santa Croce, 

On the occasion of the third congress of 
scientific men in Italy, held in Florence in 1841, 
the Tribuna di Galileo was opened by Leopoldo 
II., the last Grand Duke of Tuscany. It is on 
the first floor of the Museum of Physics and 
Natural History, a building which the scientific 
visitor to Florence should not fail to explore ; 
for, besides the exquisite little temple of Galileo, 
it contains a vast and splendid collection of scientific 
apparatus of all kinds, for the most part the remains 
of the once famous Accademia del Cimento. 

An extract from the official Guide, 1 will suffi- 
ciently explain the design : 

1 " Guide de la Tribune de Galilee," Florence, 1843. It was 
reprinted in 1861, and has long been out of print. 

414 CONCLUSION [1642 

" The temple being dedicated to the memory of 
the great Galileo, the father of experimental philo- 
sophy, and being destined to preserve the scientific 
instruments, etc. the products of his genius, and of 
that of his school, it was desired that it should be, at 
the same time, commemorative of the most famous 
epochs of Tuscan philosophy, and of the men who 
made them famous. And, in order to preserve the 
distinctively national character of the work, it was 
decided that only Tuscan artificers and Tuscan 
materials should be employed in the building and 
decorating. Thus the architect, Giuseppe Martelli, 
was Tuscan, and the artificers, the painters, and the 
sculptors were all Tuscan/' 

The building, which is said to have cost ,40,000, 
consists of (i ) a vestibule which is lighted on the left 
by a fine stained-glass window, and from which 
opens, on the right, (2) a small rectangular hall, 
which leads to (3) a semi-circular tribune. The 
interiors are entirely lined with white marble, and 
profusely decorated with frescoes, medallions, busts, 
and drawings carved in low-relief and illustrative of 
the discoveries and inventions of Galileo and his 
immediate followers. 

In the centre of the tribune stands the statue of 
Galileo by Professor Costoli ; and in compartments 
of the domed ceiling above the statue are three 
frescoes, depicting three momentous periods of his 
life the rising, the zenith, and the setting of his 
genius. In the first, we see the youthful Galileo 
watching intently the swinging lamp in the Cathedral 
of Pisa. In the second, he is presenting his telescope 
to the Doge of Venice. In the third, old and blind, 
he is seated at a table, with his left hand on a globe, 

Tribuna di Galileo, Florence, 

L To face p. 414. 


and discoursing to Torricelli and Viviani ; the parish 
priest of Arcetri, and Galileo's father confessor, are 
seen listening at the open door. 

In the (semi-circular) wall of the tribune are six 
niches ; the first, second, fifth, and sixth, contain 
busts of Castelli and Cavalieri, Torricelli and 
Viviani, the two first and the two last disciples of 
Galileo. In the third niche one sees, through a 
glass frame, two of Galileo's later telescopes, and 
the object-glass of the telescope with which he made 
all his astronomical discoveries ; we have reproduced 
a photograph of these precious relics to face p. 96. 
In the fourth niche, also glass-covered, are seen (i) 
a geometrical and military compass, (2) a loadstone 
with Galileo's armature, and (3) the index finger of 
his left hand. 

In lunettes, above the walls of the vestibule and 
rectangular hall, are four large frescoes. One, 
which faces the visitor on entering the temple, 
shows Leonardo da Vinci in presence of Ludovico 
Sforza, Duke of Milan, to whom he is enumerat- 
ing his numerous inventions. In the opposite 
lunette Volta is seen explaining his electric pile 
to the members of the French Institute, Napoleon 
and Lagrange being prominent amongst the spec- 
tators. The corresponding paintings in the hall 
represent (i) Galileo in Pisa proving the law of 
descent of falling bodies by experiments on an 
inclined plane, and (2) Viviani, Borelli, and Redi 
showing to the Grand Duke the apparent (but to 
them real) reflection of cold by a parabolic mirror. 
A thermometer is seen in the focus of the mirror, 
and a block of ice is used as the source of cold. 

416 CONCLUSION [1642 

On the pilasters are fourteen white marble 
medallions of members of the Accademia del 
Cimento, and other distinguished Italian scientists. 
And on pedestals in the vestibule are busts of the 
Grand Duke, Ferdinando II. , the friend of Galileo, 
and a patron of science ; of Prince Leopoldo, his 
brother, also a great friend of Galileo, and founder 
of the Accademia del Cimento ; of Grand Duke 
Pietro Leopoldo I., founder of the Museum of 
Physics and Natural History ; and of Grand Duke 
Leopoldo II., under whose auspices the temple of 
Galileo was erected. Scattered over the vaulted 
roofs or ceilings are ten small paintings, emblematic 
of nature, truth, perseverance, physics, philosophy, 
astronomy, geometry, mathematics, hydraulics, and 

On the floor of the hall, on stands, are four 
instruments of great size: a brass astrolabe; an 
odometer or distance-measurer ; a movable dial by 
Rinaldini, mounted in walnut, with a Tychonic 
scale in brass ; and the great crystal lens of Bregans 
of Dresden, with which Averani and Targioni- 
Tozzetti, and, many years later, our own Sir Hum- 
phrey Davy made experiments on the combustion 
of the diamond and other precious stones. Finally, 
in large glass cases,, lining the walls of the hall and 
vestibule, are preserved the most interesting speci- 
mens of the instruments, etc., belonging to the 
famous Accademia del Cimento, such as thermo- 
meters, barometers, hygrometers, gravity-meters, 
globes for experiments on the compressibility of 
water, telescopes by Torricelli, Viviani, and other 
early Italian makers; and collections of chemical 


(beautiful specimens of Florentine glass-work), astro- 
nomical, nautical, and geodetic apparatus. 1 

In 1864, the tercentenary of Galileo's birth was 
celebrated at Pisa, in a way which, if the news could 
have reached him, would have gone far to make 
amends for her ill-treatment in the flesh of her most 
famous graduate and professor. 2 

On ;th December 1892, a far more imposing 
ceremony took place in Padua, to commemorate the 
three-hundredth anniversary of Galileo's first lecture 
in that renowned seat of learning. We base the 
following account of this historical function on an 
article in " Nature/' 22nd December 1892. 

" On 6th December, the rector, Professor C. F. 
Ferraris, received in one of the courts of the old 
University (adorned everywhere with portraits of 
the most illustrious professors) delegates from the 
universities, the polytechnic schools, and Italian 
and foreign academies, amounting to nearly a 
hundred, and among them many who shed most 
lustre on contemporary science. The University 
of Cambridge was represented by Professor George 
Howard Darwin, F.R.S., who also represented the 
Royal Society, as Mr Norman Lockyer, its 
delegate, had been prevented from attending. The 
University of Oxford by Professor E. J. Stone ; 

1 At the foot of the stairs leading to the Tribune is a fine statue of 
Torricelli in white marble, but it is practically hidden in a small 
sombre recess. Surely the Museum authorities could find a more 
suitable place. 

z See " II terzo Centenario di Galileo," by Professor Benedetti, Pisa, 
1864, or Giornale di Pisa, 2ist February 1864. On 2nd October 1839, 
a fine marble statue of Galileo, by Emilio Demi, was unveiled in the 
University. The figure, larger than life, is sitting, in professor's gown, 
and holds a globe in the left hand- A partly unrolled scroll (showing 
astronomical figures) rests on the knee, and the right hand is slightly 
extended as if in the act of demonstrating. 

2 D 

4 i8 CONCLUSION [1642 

the Royal College of Physicians, London,^ by Sir 
Joseph Fayrer, F.R.S. ; the Chemical Society and 
British Association by Professor Ludwig Mond, 
F.R.S. ; the Harvard University, Cambridge, 
U.S.A., by Professor William James, and the 
Princeton University by Professor Allan Marquand. 

" The great academical celebration took place on 
7th December in the large hall of the University, 
in the presence of Signor Ferdinando Martini, 
Minister of Public Instruction, who represented the 
King of Italy. The ceremony was begun with a 
discourse, prepared for the occasion, by the rector 
magnifico, and devoted principally to a cordial 
expression of thanks to the king and to the' minister 
who represented him; to the foreign and Italian 
delegates ; and to the ladies of Padua, who had 
given the University a most beautiful banner, on 
which were various emblems indicating the history 
of the University, the genealogical tree of the 
Galilei family, and the ancient inscription above 
the door of the University Gymnasium omnium 

" Next came the commemoration of Galileo by 
Professor Antonio Favaro, who has for nearly 
fifteen [now twenty-five] years devoted himself, 
almost exclusively, to the study of the life and 
works of Galileo, and to whom was confided by 
the government the care of the national edition of 
the philosopher's works, under the auspices of the 
King of Italy. The orator kept his discourse 
within the limits marked out for him, speaking 
chiefly of Galileo at Padua. Constrained to leave 
the University of Pisa Galileo had been welcomed 
in that of Padua, where he found the 'natural 
home of his mind a theatre worthy of his talents.' 
The conditions at Padua at that time were eminently 
favourable to Galileo's work, for the Venetian 
senate granted the lecturers the utmost liberty, and 


experimental methods, which could not be learned 
from books, had been practised at the University 
for more than a century. Galileo had many 
opportunities for the development of his genius, 
both in the lecture-room and in the home, in the 
preparation of scientific publications, and in the 
workshops of scientific instrument-makers both in 
Padua and Venice. To Venice he frequently went, 
attracted by the means it afforded him for study ; by 
that grand Arsenal, which had already been sung by 
Dante, and which in his famous Dialogues is spoken 
of by Galileo with admiration ; but, above all, by 
the advantages he derived from scientific inter- 
course with eminent men who resided in the lagoon 
city. The culminating point of the discourse was 
naturally reached when the orator had to deal with 
the invention of the telescope, and with the 
astronomical discoveries made by means of it, the 
immediate result of which was the recall of Galileo 
to Tuscany. This did not aid him in his glorious 
career, or help to protect him from the attacks 
which were for a long time made on him by 
invidious adversaries. Even some of his own 
friends changed at once to implacable and 
dangerous enemies, and at last he was involved in 
all the miseries which sprang from the memorable 
trial before the Inquisition in Rome. This led the 
orator to recall the fact that, when the clouds 
assumed their most threatening aspect, the Venetian 
republic, forgetting with real magnanimity what- 
ever resentment it might have felt at Galileo's 
abandonment of his chair at Padua, offered to 
reappoint him, and to print at Venice the work 
which had brought upon him so much trouble. 

After Professor Favaro's oration, discourses 
were delivered by the foreign delegates, Holmgren, 
Fayrer, Darwin, Tisserand, Lampe, Keller, 
Foerster, Sohncke, Biasing, Lemcke, Farey, 

420 CONCLUSION [ l642 

Lanczy, Schmourlo, and by Italian delegates, 
Nardi-Dei, Mantovani-Orsetti, and Del Lungo. 
Then followed the conferring of University 
honours, of which seven had been set apart by 
the council for seven men of science, one for each 
nation, all distinguished for their devotion to the 
studies in which Galileo excelled, viz., Schiaparelli, 
Helmholtz, Thomson, Newcomb, Tisserand, 
Bredichir, and Gylden. The degree of philo- 
sophy and letters was given to the Minister 
Martini ; of natural philosophy, and of philosophy 
and letters, to the leading delegates. The ceremony 
was closed by the inauguration of a commemorative 
tablet in the large hall. 

" Of the other festivities connected with the 
celebration it would be out of place to speak 
here, and it will be better to add a list of the 
publications which were issued on the occasion. 
The oration read in the great hall by Professor 
Favaro has been published, with the addition of 
twenty-five facsimiles of documents comprising 
the various decrees of the senate concerning 
Galileo ; several autographic records of Galileo, 
chosen in order to give a more exact idea of 
what are the most precious materials for his 
biography; the frontispieces of the various 
publications issued by Galileo, and relating to the 
time of his sojourn in Padua ; the geometric and 
military compass ; the writing presenting the tele- 
scope to the Doge; and the first observations of 
the satellites of Jupiter. A portrait of the great 
philosopher, from a painting which represents him 
at the age of forty, taken in 1604, is prefixed. 

<l By favour of the University, there have also 
been published two other works, one containing 
all the notices of the studies at Padua in 1592, 
the other proving which was the house inhabited 
by Galileo and the place in which he made his 


astronomical observations. The ancient Academy 
of Padua, among whose founders Galileo is 
numbered, has issued a publication in which are 
collected several works dedicated to his memory ; 
and the students of the University have sought 
to perpetuate the remembrance of this festival by 
the publication of a 'unique number/ bringing 
together all the documents relating to the sojourn 
of Galileo in Padua. These publications will serve 
as suitable memorials of a great and most interesting 


IN the last years of his life, Galileo was anxious to have 
a complete edition of his works brought out in Latin, so 
as to be accessible to students of all nations. As we 
have already had occasion to show, this was impossible 
in Italy, owing to the most stringent orders of the Pope 
against the publication of any of his works, edita et edenda 
an order which was only partially relaxed many years 
after his death. Thus, we have seen incidentally that in 
February 1635, Fra Fulgenzio Micanzio was prohibited by 
the local Inquisitor from bringing out in Venice a reprint 
of the treatise " On Floating Bodies," which does not in 
any way relate to the Copernican doctrine. 

As, then, the presses of Italy were closed against him, 
Galileo had to look abroad for a publisher. In this way 
negotiations were opened, first about 1635, with Pierre 
Carcavi, a distinguished mathematician and litterateur of 
Paris, on the occasion of his visit to Florence ; and two 
years later, with the Elzevirs of Leyden, through the 
intermediary of Micanzio in Venice. But, after much 
correspondence, and the translation into Latin of many 
pieces, these attempts fell through, one after the other, 
and for no reason that we can now know. 

Von Gebler, who is usually very accurate, says (p. 281, 
"Galileo and the Roman Curia") that before August 1636, 
the Dialogues of 1632 had been translated into English, to 
the great delight of their author. If by this he means 
published, he must be mistaken, for the first English 
translations of the famous Dialogues and a few other 
pieces printed and published in England were those of 


Thomas Salusbury in 1661-65, as noted in the " List of 
Works Consulted " which is appended to this bibliography. 
Galileo does not appear to have had any regular corre- 
spondents in England, for, amongst the thousands of 
letters in his Carteggio^ there exists only one from George 
Fortescue 1 ; but Hobbes, Milton, and, probably, other 
English travellers, were, of course, able to give him the 
gratifying news that his works were largely read in 
England ; as, indeed, we now know from other indications. 
Thus, Tobie Matthew, writing to Bacon from Brussels, 
2ist April 1616, refers to the polemical letter of 1613 to 
Castelli; and in another letter, dated I4th April 1619, he 
introduces a Mr Richard White as a gentleman lately 
returned from Florence, where he had seen Galileo, and 
had obtained copies of his works, "On the Tides," 
" Sidereus Nuncius," " On Sun-Spots," and " On Floating 
Bodies" all of which the writer was sending on to 
Bacon. 2 

Amongst the British Museum MSS. there are early 
English translations of two of Galileo's works as follows : 

Add. MSS. 23, 139. "Of the profit which is drawen 
from the Art Mechanique and its Instruments ; A Tract 
of Sign Galileo Galilei, Florentine. Raptim ex Italico 
in Anglicum sermonem transfusum. Novemb. H, 1636, 
by Mr Robert Payen." This is evidently a translation of 
the "Scienza Meccanica" of 1594. 

Harl. MSS. 6320." The Dialogues of Galileus, etc., 
upon the two Greatest Systems of the World, etc., with a 
dedicatory preface, and an explanatory introduction To 
the Discreete Reder." This MS. bears no date, only the 
initials W. N., which are supposed to be those not of the 
translator but of a former owner. 8 

1 Dated London, i5th October 1629. Fortescue wrote, amongst 
other things, the "Feriae Academicae" (London, 1630), a series of 
essays in elegant Latin, in one of which, " Astrologorum Concessus," 
Galileo and his friends, Clavio and Griemberger, are the speakers. 

3 Bacon must also have heard a great deal about Galileo from his 
Venetian correspondents, Paolo Sarpi and Fulgenzio Micanzio. 

3 Galileo may have heard of this performance through Thomas 
Hobbes, who was travelling in Italy in 1635, and who then saw the 
great Florentine. The latter probably alludes to Hobbes in his letter 


After Galileo's death, Viviani, then hardly twenty years 
old, resolved to carry out what he knew to be the ardent 
wish of his master, and at once set about collecting from 
relatives, friends, and disciples of the great dead, books, 
MSS., and documents, relating in any way to his subject. 
His intention was to publish the works in two languages 
in parallel columns, that is to say, to give a Latin version 
of those pieces first printed in Italian, and an Italian 
version of those which originally appeared in Latin. The 
collection was to be preceded by a comprehensive Life, 
of which he has left us the design " Life of Galileo," in 3 
books I. "From Birth to Invention of the Telescope"; 

II. "From the Telescope to Death"; III. "Habitudes, 
Maladies, Sayings and Pastimes, Doctrines and Unwritten 
Opinions, Friends and Scholars, Letters of Distinguished 
Men to Galileo, Illustrations from his Printed Works." 
This was to be followed by the Works, in 4 volumes, 4to, 
in Latin and Italian, in double columns I, " Astronomical 
Works"; II. "Mechanical, Physical, Mathematical Works" ; 

III. "Suspected and Prohibited Works"; IV. "Posthumous 
Works, Collectanea, and Letters." A frontispiece (copper- 
plate) was to be prefixed to all the volumes ; and portraits 
of Galileo, Salviati, and Sagredo, were to be given. 1 

Owing to ill-health and various obstacles, chief among 
them being the ecclesiastical prohibition of 1633, and the 
still active opposition of the Jesuits, Viviani was never 
able to carry out his great design ; but through all his life 

of ist December 1635 to Micanzio, in which he says : " In the last 
few days I have had many visitors from over the mountains, and 
amongst them one of the principal men of England, who told me that 
my unfortunate Dialogues had been translated into that language." 
This would fix the date of the above MS. at some time prior to the 
middle of 1634, the date of Hobbes' departure on his travels. It 
would also go to show that the translator was known to Hobbes. 
Who was he ? I suggest this as a problem for " Notes and 

1 A short and very inaccurate biography, intended, probably, as a 
rough draft of the contemplated Life, was drawn up by Viviani in the 
form of a letter to Prince Leopoldo (afterwards Cardinal) de Medici, 
dated 29th April 1654. It was published for the first time in Salvini's 
" Fasti Consolari dell' Accademia Fiorentina," Florence, 1717- 


he diligently added to his collection of the printed and 
MS. remains of his revered master. 

Meanwhile an edition of Galileo's works appeared in 
Bologna, in 1655-56, in 2 volumes, ^.to. 1 Although 
Viviani supplied the editor with much interesting material 
hitherto unpublished, this is little more than a reproduction 
of pieces already printed separately, with two notable 
exceptions, viz. the polemical letter of 1615 to the Grand 
Duchess Cristina di Lorena, and the Dialogues of 1632. 

At Viviani's death (22nd September 1703), his fine 
library went by will to the Hospital of Santa Maria in 
Campo, Florence, and his great collection of Galilean 
remains, the result of sixty years' searching, passed into 
the hands of his nephew and heir, the Abbe Jacopo 
Panzanini. This man, ignorant or regardless of the value 
of his inheritance, made no attempt to utilise it, or to add 
to it, as he might easily have done in those days. He 
appears to have stowed the books and MSS. away in 
presses or cupboards, allowing, however, the use of them 
to students, some of whom, it is sad to say, forgot to 
return what they had borrowed. Thus, Tommaso Buona- 
venturi and Benedetto Bresciani, the editors of the first 
Florentine edition, were great sinners in this respect. 2 
Their sin would, perhaps, not be so great had they made 
better use of the materials placed at their disposal. There 
is no order or method in the arrangement, and their work 
is in other respects imperfect ; not only are the Dialogues 
of 1632 and other pieces banned by the Inquisition 
omitted, but some of those which are included are not 
published in their integrity. 

A better edition was brought out in Padua in I/44. 3 
Here also many pieces, already published, are omitted, 
but the Dialogues of 1632 are given "with ecclesiastical 
permission/' The editor, however, appears to have been 

1 " Opere di Galileo, etc. In questa nuova editione insieme 
raccolte, e di varii trattati non pm stampati accresciute." 

2 " Opere di Galileo, etc. Coll' Aggiunta di vari trattati non piu 
dati alle stampe." 3 vols. 4to. Florence, 1718. 

3 "Opere di Galileo, etc, Accresciute di Molte Cose Inedite." 
4 vols. 4to. Padua, 1744. 


obliged to prefix some saving clauses. The sentence of 
1633 and Galileo's abjuration are reprinted, and are 
followed by a declaration that the theory of the double 
motion of the earth can and must be regarded only as a 
mathematical hypothesis to facilitate the explanation of 
certain natural phenomena. Then follows, for greater 
security I suppose, Father Calmet's essay, 1 in which the 
Scriptural passages relating to the order of the world 
ought, presumably, to be interpreted in the orthodox 
fashion. As a matter of fact, however, the learned Father's 
line of argument differs little from that of Galileo. He 
seeks to show that the Bible does not propound any 
astronomical system whatever; that if it does, it is the 
popular cosmography of the Hebrews, from which it often 
borrows expressions or images, but without guaranteeing 
their accuracy ; that this cosmography is scientifically 
untenable, and, moreover, differs essentially from that of 
Ptolemy and the Peripatetics, and, therefore, people have 
no right to invoke the Scriptures in support of the latter. 
In fact, in the first centuries of Christianity, the Ptolemaic 
doctrine of a round earth was held by some fanatics as 
heretical, being opposed to the Hebrew and Scriptural 
presentment of the earth as a plain surface over which 
the heavens are spread in tent fashion. 

A few years after the appearance of the Paduan 
edition an accident befell the Galilean papers, from which 
they, or rather what remained of them, were saved by, so to 
speak, a miracle. The story is told by Professor Giovanni 
Targioni-Tozzetti in his "Notizie degli Aggrandimenti 
delle Scienze Ffsiche in Toscana" (Florence, 1780), and 
by Nelli in his " Vita e Commercio Letterario di Galileo 
Galilei J> (Lausanne, 1793). 

In the spring of 1750, the celebrated Dr Giovanni 
Lami, Keeper of the Riccardian Library in Florence, 
going one day, according to his wont, to lunch with some 
friends in the suburbs (at the "Osteria del Ponte alle 
Mosse "), and passing through the market-place, suggested 

1 "Dissertation sur le Systeme du Monde des Anciens He'breux." 
Paris, 1720. 


to Gio. Battista Nelli (his companion) to procure a Bologna 
sausage from the shop of Cioci, a pork-butcher then noted 
for his wares. Nelli did so, and brought away the purchase 
wrapped in an old MS. paper. Arrived at the tavern, he 
called for a plate, and, unrolling his sausage, remarked 
that the wrapper was a letter in Galileo's handwriting! 
Suppressing his surprise as well as he could, he cleaned 
the paper and put it into his pocket, without saying a 
word to Lami. After returning to the city, Nelli got rid 
of his friend, and flew to the pork-seller's shop, where he 
learnt that a servant, whom the proprietor did not know, 
brought him from time to time similar writings which he 
bought by weight as waste paper. Nelli purchased all 
that he then had, and, after watching for several days the 
return of the unknown domestic with another bundle, had 
at last the good fortune to meet him, and to learn the 
quarter whence the papers came. This was no other than 
Viviani's house in Via delF Amore [now Via San Antonino] 
then occupied by Carlo and Angelo Panzanini, nephews 
and heirs of the Abbe, who died in 1733. After some 
judicious enquiries Nelli found that it was the brothers 
Panzanini themselves who were guilty of the atrocity of 
selling from time to time bundles of these precious papers, 
and with a little management he procured what remained 
in their hands for the sum of eighty-eight scudi (about 
20). These comprised a great number of MSS. of 
Galileo, Viviani, Torricelli, and Borelli, and a number of 
mathematical instruments belonging to Viviani. At .the 
same time he became the possessor of the emerald ring 
which Prince Cesi gave to Galileo on his election as a 
member of the Accademia dei Lincei in 1611, and a 
collection of designs by the most celebrated architects 
of Italy. 

To this important acquisition so extraordinarily brought 
about, Nelli added, in 1754, a number of portraits of 
eminent mathematicians, forming part of the collection 
made by Viviani, another part of which came, at about 
the same time, into the hands of the astronomer, Perelli. 
It would seem that the Panzaninis had sold these many 


years previously, besides a great number of Galileo's MSS., 
books full of marginal annotations in his autograph, and 
letters from his correspondents. Most of these were 
purchased, either directly from the Panzaninis, or from 
third parties, by Felici, Cocchi, Capponi, Nelli (in 1754), 
and more recently by Campori. Ultimately all these 
collections were acquired by the Tuscan Government, and, 
with the nucleus which already existed, gathered from 
Florentine libraries and from other public and private 
sources, now form the grand collection of Galilean books 
and MSS. in the Biblioteca Nazionale in Florence. It is 
comprised in some 303 large volumes, and arranged under 
five heads or classes as follows : 

1. Before the time of Galileo 10 vols. 

2. MSS. of Galileo . . 86 vols. 

3. Contemporaries of Galileo 1 1 vols. 

4. Disciples of Galileo . . 148 vols. 

5. After the time of Galileo 48 vols. 

Besides this collection, Professor Favaro, the learned 
Director of the new edition of Galileo's Works now in 
course of publication, has catalogued over 1200 MSS. 
and documents relating to Galileo (many of which are 
his autographs) dispersed in the public and private libraries 
of Europe. 1 

Notwithstanding the zeal and industry of collectors, 
many of Galileo's papers and letters are missing. Some 
of these are mentioned in pp. 37, 120, 156, 194, ante, 
to which we may now add the loss of his later notes on 
(i) "The Mechanical Problems of Aristotle," and (2) "On 
the Movements of Animals," on which he was engaged 
only a short time before his fatal illness. No doubt many 
valuable papers were lost through the sordid action of the 
Panzaninis, and Viviani tells us that others were destroyed 
by Galileo's grandson, Cosimo, who conceived that in so 

1 " Material! per un Indice dei MSS. e Document! Galileiani non 
posseduti dalla Biblioteca Nazionale di Firenze." Raccolti per cura 
di Antonio Favaro, Venice, 1894. 


doing he was offering up a proper sacrifice before devoting 
himself to the life of a missionary priest 1 

During the years 1808 to 1811 a new edition of 
Galileo's Works appeared in Milan, in 13 volumes, 8vo, of 
which it is only necessary to say that the first 12 volumes 
are a simple reprint of the Paduan edition, whilst the 
1 3th and last contains matter not found in that collection, 
it is true, but yet nothing that had not been published 
before. Another edition, and the worst of all, appeared 
in Milan in 1832, and forms volumes xx. and xxi. of 
Bettoni's " Biblioteca Enciclopedica Italiana." 

The more recent editions of Alberi and Favaro are 
noted in detail in the "List of Works Consulted" 
subjoined to this notice. 

A bibliography would not be complete without a 
reference to the extraordinary collection of forged docu- 
ments, with which the French Academy of Sciences was 
convulsed in the years 1867-1869. They were acquired 
by Michel Chasles, a member of the Academy, and by 
him presented to that body in batches. They consisted 
of letters and documents bearing the names of Galileo, 
Viviani, Pascal, Newton, Milton, Huygens, Louis XIV., 
and other well-known persons of the period; and they 
went to show, amongst other startling things, (i) that 
Pascal borrowed from Galileo the idea of universal 
gravitation, and that Newton in his turn borrowed from 
both, without acknowledgments ; and (2) that Galileo's 
blindness was feigned in order to induce the Inquisition 
authorities to relax their surveillance ; and that he really 
became blind only a short time before death. 

The briefest rteumt of these papers will suffice here, 
as the curious reader will find them, and the discussions 
to which they gave rise, fully reported in the Comptes 

1 Professor Favaro thinks there is little or no foundation for this 
charge, and concludes, after reviewing the evidence, that if Cosimo 
did burn any papers of his grandfather, they were such as were of no 
importance, and of which Viviani already had copies, or, and this is 
the more likely, they were his own youthful lucubrations of which his 
later and ascetic temper could not approve. 


Rendus for the years mentioned, and the history of the 
forgeries in Bordier and Mabille's " Une Fabrique de 
Faux Autographes, ou R6cit de 1' Affaire Vrain Lucas," 1 

It would appear from these documents that in the last 
years of his life, Galileo discovered a satellite of Saturn 
and made other astronomical observations, which, with 
some found in Kepler's MSS. (which had come into 
Galileo's hands), exceeded in extent and accuracy the 
subsequent observations of Cassini, Bradley, and Pound, 
and of which Newton availed himself in 1725, in the third 
and perfected edition of his " Principia." Furthermore : 
Galileo had deduced theoretically, from Kepler's Second 
Law, that the reciprocal attraction of the heavenly bodies 
ought to be in the inverse ratio of the squares of the 
distances. He communicated this discovery, as also his 
latest astronomical observations and those of Kepler, to 
Pascal, and upon these materials the latter based his 
Celestial Mechanics, including the calculation of the 
planetary masses, and wrote a treatise on the subject, a 
copy of which he sent to Galileo in 1641. 

In 1652, Boyle put Pascal in communication with 
Newton [then of the mature age of ten years !], and in 
1654, Pascal communicated to Boyle and Newton the 
aforesaid observations of Galileo and Kepler, together 
with his own Celestial Mechanics, and calculations of the 
planetary masses. In 1687, Newton published (in the 
" Principia ") Pascal's work as his own, but spoilt it by 
the employment of data less accurate than those of 
Galileo and Kepler, of which, indeed, he made no use 
until 1725 (as stated above), or seventy-one years after 
receiving them ; and then, instead of mentioning Galileo 
and Kepler, to whom he was really indebted, he quoted 
the work of later astronomers who had arrived at similar 
results. The communications made to Newton by Pascal, 
and Newton's usurpation of them were facts known to 
many scientific men in France and England ; but nothing 
was said about them until Newton had committed a 

1 Paris, 1870. On the forgeries of Vrain Lucas is founded 
Alphonse Daudet's novel, " L'lmmortel," 


further imprudence. In a letter to Huygens he appears 
to have used some disdainful language abouf Pascal; 
Huygens thereupon brought the whole matter before the 
French Academy of Sciences, that jealous body com- 
plained to Louis XIV., who in his turn complained to 
James II. of England. The result was that Newton 
withdrew his defamatory remarks, Louis XIV. expressed 
his gratitude to Newton (to whom, strange to say, was 
left all the glory which belonged to Pascal and Galileo), 
and everybody was content! The affair was hushed up, 
and soon entirely forgotten, until revived by the publication 
of M. Chasles' wondrous " find." So much for the Galileo- 
Pascal-Newton story. 

As regards the fable of Galileo's blindness, it would 
seem, from his letters and those of Viviani, Milton, and 
others, that his sight became enfeebled only in 1637-38 ; 
that up to September 1641 he was able to read and write, 
and only complained of fatigue of the eyes ; and that he 
became totally blind only towards the end of 1641, that is, 
a few weeks before death. Galileo, who, probably, never 
wrote a line in French, is made to say, in a letter of 
28th November 1639, to Louis XIII. of France: 

"Du reste je veux bien assurer Vostre Majest6 que, 
quoique ce soit pour moy une grande privation de ne 
pouvoir continuer mes observations astronomiques, je 
commence a my resigner, et je m'estime encore heureux 
qu'a mon age, et apres tant de tribulations, je puisse encore 
lire et escrire, ce qui est pour moy une grande satisfaction. 
Quant a certains propos que des gens tiennent et font 
circuler a cet egard, je ne cherche nullement a les 
d6mentir, d'autant plus que c'est un moyen d'estre 
moms obsed par mes ennemis, c'est & dire, par les 
Inquisiteurs, qui ne cessoint de me faire surveiller. Nous 
nous sommes mesme servi du pr^texte de c<cit pour 
qu'on me laisse plus en repos et & moy mesme." 

As to this fable, there are two well-established facts, 
which would seem to lend it some little support (i) It 
is certain that Galileo's blindness was due to glaucoma. 
(2) In recent years a letter of Alberto Galilei (nephew) to 


Galileo, dated igth April 1640, has been brought to light, 
from which it would appear that towards the end of 
1639 Galileo had recovered somewhat the use of his eyes, 
Professor Favaro, however, says (and there can be no better 
judge) that, in all probability, the passage is either an 
equivoque, or a question of being able to distinguish, more 
or less, the day from the night. 1 

1 " Galileo e Suor Maria Celeste," p. 221. 


Le Opere di GALILEO GALILEI, prima edizione completa, 1 con- 
dotta sugli autentici manoscritti palatini, e dedicata a S, A. I. e R. 
Leopoldo II granduca di Toscana, Firenze, societa editrice fioren- 
tina^ 1 842- 1856. Tomi XV e uno di supflemento. 

Patrono dell' edizione : S. A. I. e R. il granduca LEOPOLDO II. 

Direttore : EUGENIO ALBERT. 

Coadiutore : CELESTINO BIANCHI, per i primi sette volumi. 

Tomo primo (1842). 

Lettera dedicatoria a S. A. I. e R. il granduca Leopoldo II, 
patrono dell' edizione. 

Prefazione generale. 

Dialogo dei due massimi sistemi del mondo, tolemaico e 

Tomo secondo (1843). 

Prefazione con elenco ragionato degli oppositori al sistema 

Lettera di GALILEO a lacopo Mazzoni, del 30 maggio 1597. 

Lettera di GALILEO al p. e Benedetto Castelli del 21 dicembre 

Lettera di GALILEO a monsignor Dini del 16 febbraio 1614 
ab inc. 

Lettera di GALILEO al medesimo del 23 marzo 1614 ab inc. 

Lettera di GALILEO alia granduchessa Cristina di Lorena 
del 1615. 

Lettera di GALILEO a Francesco Ingoli, nella primavera 
del 1624. 

Esercitazioni filosofiche di ANTONIO Rocco intorno al dialogo 
dei massimi sistemi. 

1 This is by no means a complete, or even, so far as it goes, an accurate, 
presentation of Galileo's works and writings. This can be seen by comparing 
it with Favaro's national edition, now in course of publication, and of which 
twelve out of twenty volumes have already appeared. 


Postille di GALILEO alle suddette esercitazioni. 
Discorso di LODOVICO DELLE COLOMBE contro al moto della 

Postille di GALILEO al suddetto discorso. 
Discorso sopra il flusso e reflusso del mare. 

Tomo terzo (1843). 

Trattato della sfera o cosmografia. 
Sidereus Nuncius. 

Lettere intorno alle apparenze della Luna. 
De phaenomenis in orbe Lunae etc., auctore JULIO CESARE 

Postille di GALILEO all' opera suddetta, 
Lettere intorno alle macchie solari. 

Tomo quarto (1844). 

Ai lettori. 

De tribus cometis anni 1618 disputatio astronomica, publice 
habita in collegio romano societatis Jesu ab uno ex patribus 
eiusdem societatis. 

Discorso delle comete di MARIO GUIDUCCI. 

Libra astronomica ac philosophica etc., auctore LOTHARIO 
SARSIO sigensano [HORATIO GRASSIO salonensi], 

Postille di GALILEO alia Libra astronomica. 

II Saggiatore di GALILEO. 

Ratio ponderum librae ac simbellae etc., auctore LOTHARIO 

Postille di GALILEO alia suddetta opera. 

Tomo quinto (Parte prima, 1846). 

Alcuni esemplari hanno la prima parte del tomo quinto, e la prima 
sezione della seconda in lingua italiana, altri in latino. 

Prefazione di EUGENIO ALBERI nella quale si dimostra che 
tutti i lavori condotti da Galileo intorno i Satelliti di Giove, e 
che da due secoli si reputavano perduti, esistono fra i manoscritti 
galileiani della i. e r. biblioteca palatina de' Pitti. 

Tavole dei moti medi de'Satelliti di Giove istituite da GA- 
LILEO ecc. 

Osservazioni originali e calcoli intorno i Satelliti di Giove. 


Giustificazioni delle lacune che si riscontrano tra le osserva- 
zioni di GALILEO intorno i Satelliti di Giove. 
Calcoli ed effemeridi. 
Notae conclusione. 

(Parte seconda, 1853). 

Lavori del padre RENIERI intorno ai Satelliti di Giove. 

Le operazioni astronomiche di GALILEO. 

Frammenti di tre lezioni di GALILEO intorno la Stella nuova 
del 1604. 

Frammenti astronomici di GALILEO. 

KEPLERI Dissertatio in Nuncium sidereum. 

KEPLERI NTarratio de observatis a se Satellitibus Jovis. 

KEPLERI Periochae ex introduction in Martem. 

Lettera del p. FOSCARINI sul sistema copernicano. 

CAMPANELLAE Apologia pro Galilaeo. 

Dissertazione del p. CALMET intorno alia cosmogonia degli 

Lettera di MARIO GUIDUCCI al p. Galluzzi intorno le comete. 

KEPLERI Spicilegium ex trutinatore Galilaei. 

Appendix ad spicilegium. 

KEPLERI Admonitio ad bibliopolas. 

Discorso di A. DE FILIIS sulle Macchie solari di Galileo. 

Tomo ststo a decimo (1847-1853). 

Contengono un avvertimento e 1'epistolario, composto di 1376 
lettere, dal 1588 al 1642, diviso in due parti. La prima di due 
volumi (VI e VII, 1847-1848) comprende le lettere di GALILEO 
che sono 296. L'altra in tre volumi (VIII, IX, e X, 1851-1853) 
che coruprende le lettere a lui dirette^ in numero di 931, e fra 
terzi a lui relative, che sono 149. 

Tomo undecimo (1854), 

Avvertimento all 1 opera seguente. 
Sermon es de motu gravium di GALILEO. 
Delia scienza. meccanica di GALILEO. 

NTote e proposizioni intorno le meccaniche di VINCENZO 

Trattato di fortificazione di GALILEO con avvertimento. 


Le operazioni del compasso geometrico e militare di GALILEO 
con avvertimento. 

Usus et fabrica circini proportionis etc, opera et studio BAL- 

Difesa di GALILEO contro alle calunnie del Capra. 

Tomo duodecimo (1854). 


Discorso di GALILEO delle cose che stanno in su Pacqua o 
che in quella si muovono. 

Lettera di TOLOMEO NOZZOLINI a monsignor Marzimedici 
nella quale si pronmovono alcune difficolta intorno al libro di 

Lettera di GALILEO al Nozzolini in risoluzione delle accennate 

Discorso apologetico di LODOVICO DELLE COLOMBE intorno al 
suddetto discorso dei galleggianti di Galileo. 

Considerazioni di VINCENZO DI GRAZIA intorno al medesimo 

Risposta di GALILEO, sotto nome del p. Castelli, alle oppo- 
sizioni di Lodovico delle Colombe e di Vincenzo di Grazia. 

Note al discorso dei galleggianti. 

Esperimenti del cav. Gio. BATTA VENTURI intorno ai gal- 

Tomo tredicesimo (1855). 


Discorsi e dimostrazioni matematiche intorno a due nuove 
scienze attinenti alia meccanica ed ai movimenti locali ; altri- 
menti detti " Dialoghi delle nuove scienze." 

Tomo quattordicesimo (1855). 

Illustrazioni del VIVIANI e del GRANDI ai Dialoghi delle 
nuove scienze. 

Trattato delle resistenze principiato da VINCENZO VIVIANI 
per illustrare le opere di Galileo, compiuto e riordinato dal p. 

Note del p. GRANDI al trattato del moto naturalmente 

Scienza universale delle proporzioni, spiegata da GALILEO 
nella quinta giornata, con nuovo ordine distesa dal VIVIANI. 


Componimenti minori e frammenti diversi in materie scien- 
tifiche di GALILEO. 

La bilancetta ecc. di GALILEO. 

Note del MANTOVANI, del CASTELLI, e del VIVIANI alia 

Parere sopra una macchina per alzare acqua. 

Lettere intorno alia stima di un cavallo. 

Parere intorno all' angolo del contatto. 

Considerazioni sopra il giuoco de 3 dadi. 

Risposta al problema : onde avvenga che V acqua a chl 
v' entra appaia prima fredda e poi calda pih dell' aria temperata. 

Parere su di una macchina da pestare. 

Pensieri sulla confricazione. 

Awertenza intorno al camminare del cavallo. 

Theorica speculi concavi sphaerici. 

Problemi vari. 

Pensieri vari. 

DelF oriuolo a pendolo, lettera di VINCENZO VIVIANI. 

Tomo quindicesimo (1856). 

Due lezioni di GALILEO intorno alia figura, sito, e grandezza 
delP Inferno di Dante precedute da un avvertimento degli editori. 

Postille e correzioni all' Orlando furioso precedute da un 
avvertimento degli editori. 

Considerazioni alia Gerusalemme liberata. 

Due lettere a Francesco Rinuccini nelle quali si paragona il 
Tasso con TAriosto, 

Discorso di GIUSEPPE ISEO sopra il poema di M. Torquato 

Capitol o in biasimo della toga. 

Quattro sonetti. 

Abbozzo di una commedia. 

Racconto istorico della vita di Galileo scritto da VINCENZO 

Bibliografia Galileiana. 

Aggiunte e correzioni a diversi volumi della collezione. 

Suppkmento (1856). 


E. ALBERI. Esame della biografia di Galileo scritta da F. 


Lettere (186) inedite dirette a Galileo dal 1592 al 1641, fra 
le quali a pag. ir una di GALILEO all' abate Giugni da Venezia, 
ii giugno 1605. 

Appendice relativa al processo di Galileo. 

E. ALBERI. DelForologio a pendolo di Galileo e di due 
recenti divinazioni del meccanismo da lui immaginato. 

Due lettere importantissime di GALILEO, una relativa alia sua 
condanna, 1'altra ai tentativi da lui fatti per la misura della 

Le Opere di Galileo Galilei. Edizione Nazionale sotto gli 
auspicii di S. M. il Re d'ltalia. Direttore, Antonio Favaro. 
Coadiutore letterario, Isidoro del Lungo. Assistente per la cura 
del testo, Umberto Marchesini. Consultori, V. Cerruti, A. 
Genocchi (>J<). G. Govi (>f<). G. V. Schiaparelli. Firenze, tip. 
G. Barbera, 1890-1902. . . . 

Volume Primo (1890). luvenilia. Theoremata circa cen- 
trum gravitatis solidorum. La Bilancetta. Tavola delle pro- 
porzioni delle gravita in specie de i metalli e delle gioie pesate 
in aria e in aqqua. Postille ai libri de sphaera et cylindro di 
Archimede. De motu. 

Volume Secondo (1891). Breve instruzione air architettura 
militare. Trattato di fortificazione. Le Mecaniche. Lettera a 
lacopo Mazzoni. Trattato della Sfera owero Cosmografia. 
De motu accelerate. Frammenti di lezioni e di studi sulla nuova 
Stella dell' ottobre 1604. Consideration astronomica circa la 
Stella nova delP anno 1604 di Baldesar Capra, con postille di 
Galileo. Dialogo de Cecco di Ronchitti da Bruzene in per- 
puosito de la Stella nuova. Del compasso geometrico e militare : 
saggio delle scritture antecedenti alia stampa. Le operazioni 
del compasso geometrico e militare. Usus et fabrica circini 
cuiusdam proportions, opera et studio Balthasaris Caprae; con 
postille di Galileo. Difesa contro alle calunnie et imposture di 
Baldessar Capra. Le matematiche nelP arte militare. 

Volume Terzo. Parte prima (1892). Sidereus Nuncius. 
loannis Kepleri Dissertatio cum Nuncio Sidereo. Martini 
Horky Brevissima peregrinatio contra Nuncium sidereum. 
Quatuor problematum contra Nuncium sidereum confutatio per 
loannem Wodderbornium. loannis Kepleri Narratio de obser- 
vatis a se quatuor lovis satellitibus. loannis Antonii Roffeni 
Epistola apologetica contra peregrinationem Martini Horkii. 


Dianoia astronomica, optica, physica, auctore Francisco Sitio; 
con postille di Galileo. Di Ludovico delle Colombe contro il 
moto della terra; con postille di Galileo, Nuntius Sidereus 
Collegii romani. De lunarium montium altitudine problema 
mathematicum, lulii Caesaris La Galla De phaenomenis in 
orbe lunae novi telescopii usu nunc iterum suscitatis ; con postille 
di Galileo. 

Volume Quarto (1894). Diversi fragmenti attenenti al trattato 
delle cose che stanno su 1'acqua. Discorso intorno alle cose 
che stanno in su Tacqua o che in quella si muovono. Considera- 
zioni di Accademico Incognito; con postille e frammenti della 
risposta di Galileo, Operetta intorno al galleggiare dei corpi 
solidi di Giorgio Coresio. Errori di Giorgio Coresio nella sua 
operetta del galleggiare della figura raccolti da d. Benedetto 
Castelli. Con correzioni ed aggiunte di Galileo. Lettera di 
Tolomeo Nozzolini a monsignor Marzimedici arcivescovo di 
Firenze. Lettera a Tolomeo Nozzolini. Discorso apologetico 
di Lodovico delle Colombe. Consider azioni di Vincenzio di 
Grazia, Frammenti attenenti alia scrittura in risposta a Lodovico 
delle Colombe e Vincenzio di Grazia. Risposta alle opposizioni 
di Lodovico delle Colombe e di Vincenzio di Grazia contro al 
trattato delle cose che stanno su Tacqua o che in quella si 

Volume Quinto (1895). Apellis latentis post tabulam tres 
epistolae de maculis solaribus. Apellis latentis post tabulam de 
maculis solaribus et stellis circa lovem errantibus accuratior 
disquisitio; con postille di Galileo. Istoria e dimostrazioni 
intorno alle macchie solari e loro accidenti, comprese in tre 
lettere scritte a Marco Velseri. Frammenti attenenti alle lettere 
sulle macchie solari. Lettera a D. Benedetto Castelli. Lettere 
a mons. Piero DinL Lettera a madama Cristina di Lorena 
granduchessa di Toscana. Considerazioni circa Topinione coper- 
nicana. Discorso del flusso e reflusso del mare. Francisci 
Ingoli De situ et quiete Terrae disputatio. Proposte per la 
determinazione della longitudine. 

Volume Sesto (1896). De tribus cometis anni MDCXVIII 
disputatio astronomica publice habita in Collegio Romano 
Societatis Jesu ab uno ex patribus eiusdem Societatis. Discorso 
delle co mete, con alcuni frammenti ad esso attenenti. Lotharii 
Sarsii Sigensani Libra astronomica ac philosophica ; con postille 
di Galileo. Lettera di Mario Guiducci al P. Tarquinio Galluzzi. 


II Saggiatore. Lotharii Sarsii Sigensani Ratio ponderum et 
simbellae; con postille di Galileo. Lettera a Francesco Ingoli 
in risposta alia Disputatio de situ et quiete terrae. Scritture 
concernenti il quesito in proposito della stima d'un cavallo. 
Scritture attenenti all' idraulica. 

Volume Settimo (1897). I due massimi sistemi del mondo. 
Frammenti attenenti al dialogo sopra i due massimi sistemi 
del mondo. Dal libro di G. B. Morin "Famosi et Antiqui 
Problematis de Telluris Motu vel Quiete," con le note di 
Galileo. Esercitazioni filosofiche di A. Rocco, con postille di 

Volume Ottavo (1898). Le nuove scienze. Della forza della 
percossa. Sopra le difinizioni delle proporzioni d'Euclide. 
Frammenti attenenti ai discorsi e dimostrazioni matematiche 
intorno a due nuove scienze. Le operazioni astronomiche. 
Lettera al Principe Leopoldo di Toscana in proposito del cap. 
L. del " Litheosphorus " di Fortunio LicetL Frammenti attenenti 
alia lettera al Principe Leopoldo di Toscana. 

Scritture di data incerta. 

A proposito di una macchina con gravissimo pendolo adattato 
ad una leva. A proposito di una macchina per pestare Di 
alcuni effetti del contatto e della confricazione. Sopra le scoperte 
de i dadi. Intorno la cagione del rappresentarsi al senso fredda 
o calda la medesima acqua a chi vi entra asciutto o bagnato. 
Problems Nell' arte navigatoria. Frammenti geometrici. 

Volume Nono (1899). La figura, sito, e grandezza del- 
ITnferno di Dante. Considerazioni al Tasso. Postille air Ariosto. 
Argomento e traccia d'una commedia. Poesie e Frammenti. 
Canzone di Andrea Salvador! per le Stelle Medicee, scritta e 
corretta di propria mano da Galileo. Saggio di alcune esercita- 
zioni scolastiche di Galileo. 

Volume Decimo (1900) Carteggio, 1574-1610. 

Volume Undecimo (1901). Carteggio, 1611-1613. 

Volume Duodecimo (1902). Carteggio, 1614-1619. 

In course of publication. 

Volume Decimoterzo. Carteggio, 1620-1628. 
Volume Decimoquarto. Carteggio, 1629-1632. 
Volume Decimoquinto. Carteggio, 1633. 
Volume Decimosesto. Carteggio, 1634*1636. 


Volume Decimosettimo. Carteggio, 1637-1638. 
Volume Decimottavo. Carteggio, 163 9-1 642.* 
Volume Decimonono. Document!. 
Volume Ventesimo. Indici. 

Besides editing this splendid collection, which alone is a 
monumental work, Professor Favaro has written considerably 
over one hundred papers, essays, and detailed studies, each 
illustrative of some point in the life and writings of Galileo. 
Some of these have been published in book form, but far the 
greater part is scattered through the journals of learned societies 
in Italy, dating back to 1878. Fortunately for the student, much 
of the information they contain is reproduced in the numerous 
(historical and critical) introductions and notes which enrich the 
new national edition of Galileo's works and correspondence. In 
the following list we give a few as of general interest, besides 
which some other papers by the same author will be found 
quoted in the body of our work. 

FAVARO, PROF. ANTONIO. "Galileo e lo Studio di Padova," 

2 vols. Florence, 1883. 
"Scampoli Galileiani." 12 Series (Atti e Memorie della 

Accademia di Scienze^ Lettere\ ed Arti in Padova). 

" Document! Inediti per la Storia dei Manoscritti Galileiani 

nella Biblioteca Nazionale di Firenze." Rome, 1886. 
" Miscellanea Galileiana Inedita : Studi e Ricerche " 

(Memorie del .R. Istituto Veneto di Scienze, Lettere, ed 

Aril). 1887. 

" Galileo Galilei e Suor Maria Celeste." Florence, 1891. 

" Nuovi Studi Galileiani >; (Memorie del R. Istituto Veneto 

di Sdenze^ Lettere^ ed Arti). 1891. 
" Galileo ed il suo Terzo Centenario Cattedratico nelP 

Universita di Padova" (Natura ed Arte). Milan, 1893. 

The following items are arranged in chronological order, 

VIVIANI, VINCENZIO. " Racconto Istorico della Vita di Galileo." 
Florence, 1654 (printed in vol. xv. of Alb&ri's Edition, 
quoted above). 

1 The Carteggio contains considerably over 4000 letters from, to, and 
concerning, Galileo, of which 420 are Galileo's. 


SALUSBURY, THOMAS. " Mathematical Collections and Transla- 
tions," 2 vols. London, 1661 and 1665. 

Contains following works of Galileo : 

(1) " On the System of the World." 

(2) "Epistle to the Grand Duchess, Mother, Concerning the Authority 

of Scripture in Philosophical Controversies." 

(3) " Mathematical Discourses and Demonstrations touching Two 

New Sciences, Pertaining to Mechanics and Local Motions." 

(4) " On Mechanics, with some Additional Pieces." 

(5) " Discourse on Natation." 

Note. Part II. of the Second Volume contains a "Life of Galileo," in five 
books. Most of the copies of this part were destroyed in the Great 
Fire of London, and very few perfect copies now exist ; that in the 
British Museum is imperfect. 

WESTON, THOMAS. " Mathematical Discourses Concerning Two 
New Sciences relating to Mechanics and Local Motion, 
in Four Dialogues, by Galileo Galilei, Chief Philosopher 
and Mathematician to the Grand Duke of Tuscany. 
With an Appendix Concerning the Centre of Gravity of 
Solid Bodies." Done into English from the Italian. 
London, 1730. 
NELLI, Gio. BATISTA CLEMENTE. "Vita e Commercio 

Letterario di Galileo Galilei," 2 vols. Lausanne, 1793. 
MONTUCLA, J. F. "Histoire des Mathematiques depuis leur 

Origine jusqu'a Nos Jours," 3 vols. Paris, 1802. 
NEUMAYR, ANTONIO. "Illustrazione del Prato della Valle, ossia 
della Piazza delle Statue di Padova," 2 parts. Padua, 

VENTURI, GIAMBATISTA. "Memorie e Lettere Inedite Finora 
o Disperse di Galileo Galilei," 2 parts. Modena, 1818- 

MOLL, Dr G. " On the first Invention of Telescopes, collected 
from the Notes and Papers of the late Prof. Van Swinden " 
(Journal of the Royal Institution), London, 1831, 
DRINKWATER-BETHUNE, J. E. " Life of Galileo. With Illustra- 
tions of the Advancement of Experimental Philosophy." 
(Library of Useful Knowledge). London, 1833. 
POWELL, BADEN. " Historical View of the Physical and Mathe- 
matical Sciences from the Earliest Ages to the Present 
Times' (Lardner's Cabinet Cyclopaedia). London, 1834. 
WHEWELL, WILLIAM. "History of the Inductive Sciences," 3 
vols. London, 1837 ; or later editions. 


BREWSTER, SIR DAVID. "Martyrs of Science, or Lives of 
Galileo, Tycho Brah, and Kepler." London, 1841. 

The Biography of Galileo first appeared in Lardner's Cabinet 
Cyclopaedia "Eminent Literary and Scientific Men of Italy, 
Spain, and Portugal," 2 vols. London, 1835. 

LIBRI, GUILLAUME. " Histoire des Sciences Math^matiques en 

Italie depuis la Renaissance des Lettres jusqu'a la fin du 

17 Sicle," 4 vols. Paris, 1841. 
" Essai sur la Vie et les Travaux de Galilee." Paris, 1841. 

(Reprint from the Revue des Deux Mondes of isth 

July 1841). 
ROSINI, GIOVANNI. " Descrizione della Tribuna di Galileo in 

Firenze." Florence, 1841. 
ANTINORI, VINCENZO. "Notices sur La Tribune de Galilee." 

Florence, 1843. (Reprinted 1861). 
GRANT, ROBERT. " History of Physical Astronomy." London, 

ARAGO, FRANCOIS. " Oeuvres Completes, de," edited by J. A. 

Barral, 3 vols. Paris, 1855. 
CHASLES, PHILAR&TE. " Galileo Galilei : Sa Vie, Son Proces, et 

Ses Contemporains." Paris, 1862, 
VARIOUS AUTHORS. " Nel Trecentesimo Natalizio di Galileo in 

Pisa, 18 Febbraio 1864." Pisa, 1864. 
PARCHAPPE, MAX. " Galilee, Sa Vie, Ses D&ouvertes, et Ses 

Travaux." Paris, 1866. 
PONSARD, FRANCOIS. " Galilee : Drame en Trois Actes en Vers." 

Paris, 1867. 
MARTIN, TH. HENfei. " Galilee : Les Droits de la Science, et la 

Mdthode des Sciences Physiques." Paris, 1868. 
FIGUIER, Louis. " Vies des Savants Illustres depuis 1'Antiquite 

jusq'au 19 Si&cle," 4 vols. Paris, 1869, 
ANONYMOUS (MRS OLNEY). " Private Life of Galileo. Compiled 

Principally from his Correspondence and that of his 

Eldest Daughter, Sister Maria Celeste, Nun in the Fran- 

ciscan Convent of St Mathew in Arcetri." London, 1870. 
NEWCOMB, SIMON. "Popular Astronomy. London, 1878." 
CLERKE, A. M. "Biography of Galileo," in Ency. Brit Ninth 

Edition. Edinburgh, 1879. 
GEBLER, KARL VON. "Galileo Galilei and the Roman Curia." 

(Mrs Sturge's Translation). London, 1879. 
BALL, SIR R. S. " Story of the Heavens." London, 1885 ; or 

later editions. 


WEGG-PROSSER, F. R. "Galileo and his Judges," London, 

Govi, GILBERTO. "The Compound Microscope invented by 

Galileo." (Journal of the Royal Microscopical Society}. 

London, 1889. 
BERRY, ARTHUR. "Short History of Astronomy." London, 

GORI, PIETRO- "Le Preziosissime Reliquie di Galileo Galilei." 

Florence, 1900. 
NEWCOMB, SIMON. " The Stars." London, 1901. 


Accademia dei Lincei, 128, 132, 155, 

del Cimento, 363, 392 

della Crusca, 18, 29, 388 

Acoustics, Galileo's experiments in, 


Air, specific gravity of, 350 
Apology, Galileo's, 157 
Aproino, Paolo, advice re Dialogue 

of 1632, 264; tribute to Galileo, 

Arcetri, Galileo's villa at, 235 ; 

memories of Galileo, 237 ; called 

by Galileo " my prison," 386 ; 

visited by Milton, 390 
Archimedes and Hiero's crown, 14 
Ariosto, 29, 286, 411 
Aristotle, doctrines of, 8, 22-6, 56, 

100, no, 123, 130, 137, 147, 150, 

248 et s&q.> 350 et seq. t 370, 394, 


Arrighetti, Andrea, 327, 333 
Astrology, 54, 64 
Aula Magna, Padua University, 57 

BACON, FRANCIS, 53, 65, 424 

Balance, Hydrostatic, 14 

Barberini, Cardinal Antonio, 264, 

292* 307, 333, 336, 380 
Cardinal Francesco, 263, 270, 

273, 278-80, 285, 300, 321-2, 380-1 
Cardinal Maffeo. See Urban 


Beams, strength of, 360 
Bellarmine, Cardinal, 51, 127, 155, 

163, 166-9, 196, 275, 294, 314, 


Bellosguardo, Galileo's villa at, 192 
Bentivoglio, Cardinal, 287-8, 290, 


Bibliography, Galilean, 423-33 
Bologna-stone, phosphorescent, 391 
Borgia, Cardinal, 321-2 
Boscaglia, Professor, 149 
Brane", Tycho, 36, 50, 55, 65, 394 

Bridge with cycloidal arches, 22 
Bruno, Giordano, burnt, 325 
Burgi and pendulum-clock, 399 

CACCINI, FATHER, denounces Gali- 
leo, 152, 155; begs pardon, 159 

the sculptor, 404, 406 

Calculus, indivisible or fluxional, 120, 

Calmet, Father, cosmography of the 
Bible, 319, 427 

Campanella, Tommaso, 226, 271 

Canalisation schemes, 242 

Capra, claims to be true inventor of 
the geo. and mil. compass, 44-6 

Cardan, the algebraist, and astrology, 


Castelli, Benedetto, forbidden to teach 
Coperhicanism, 9, 147 ; on the air 
thermometer, 51 ; on Galileo's load- 
stone, 6 1 ; on Saturn's ring, 113; 
defends Galileo's treatise on Float- 
ing Bodies, 144 ; Galileo's letter to, 
149, 202, 215, 219, 226, 328, 379* 
385> 400 

Catenary curve, 359 

Cavalieri, Bonaventura, 120, 401 

Cesalpino, Andrea, 8 

Cesi, Prince, 112, 128, 156, 200, 240 

Chiaramonti, Scipione, 256, 343 

Christmann, 103 

Church of Santa Croce, 2 ; Galileo's 
grave and monument in, 402-6 ; 
sentence of Inquisition publicly read 
in, 327 

Santa Maria Novella, Galileo 

denounced from pulpit of, 152 

Ciampoli, Giovanni, 156, 272, 328,413 

Cigoli, the painter, 7, 134 

Clavio, Cristoforo, 19, 101, 127 

Clock, pendulum, 396 

Cohesion, molecular, 349, 360, 370 

Comets of 1618, 181 

Compass, geometrical andj military, 
42,93, 119 

Concords, musical, 363 




Constellations, the, 89 

Conti, Cardinal, the Bible and science, 


Copernicus, book suspended, 164 
Coresio, Giorgio, 144 
Cosimo II., Grand Duke, 44, 57, 62, 

64,85,96, 117, 121, 123, 126, 128, 

137, 158, 170, i77> 215, 404 
Costoli, his statue of Galileo, 414 
Cremonino, Cesare, 101 
Cristina, Grand Duchess, 64, 149 ; 

Galileo's letter to, 157, 204 
Cycloid, the, 22, 401 

DANTE'S " Inferno," 18 

Da Vinci, Leonardo, 23, 88 

De Dominis, Marc' Antonio, 325 

D'Elci, Arturo, 144 

Delle Colornbe, Lodovico, 144 

Del Monte, Cardinal, 21, 127-8, 155, 


Guidobaldo, 18, 20, 22, 28, 34 

De Medici, Giovanni, his dredger, 

De Medici, Leopoldo, 53, 96, 239, 

392, 399, 4i6, 425 

Marie, and the telescope, 99 

Demi, Emilio, bust and statue of 

Galileo, 193, 417 
" De Motu Gravium," 24 
De Noailles, Comte, 345, 347, 380 
De Peiresc, Niccol6, 209, 345, 380 
Descartes, 371, 390 
Dialogue on the Two Systems of the 

World, 214, 226; plan of, 243; 

contents of, 248 ; value of, 261 ; 

publication of and consequences, 

263; sale of interdicted, 271 ; and 

numerous references in subsequent 

Dialogues on the two new Sciences, 

333, 344; publication of, 346; 

contents of, 349 ; value of, 366 
Digges, father and son, 62 
Di Grazia, Vincenzio, 145 
Diodati, EHa, 239, 339, 366, 372, 

378, 388 
Di Zuniga, Diego, book suspended, 

Drebbel, Cornelius, 53, 209 

' ' EPPUR si MUOVE," 324 

Faculae (sun-spots), 131 
Falling bodies, laws of, 25, 350 
Favaro, Professor, 8, 13, 21, 28, 30, 
41, 49, 109, 112, 168, 175, I93> 
196, 288, 322, 418, 429, 430, 433, 

Ferdinando I., Grand Duke, 13, 1 8, 

20, 6 1, 64 
Ferdinando II., 53, 206, 215, 225, 

239, 242-3, 271,283, 309, 333, 375, 

380, 3^4-5, 400, 403, 4i6 
Firenzuola, Father, 294, 299, 300, 


Floating bodies, discourse on, 136 
Fogginis, the, sculptors, 405 
Foscarini, his book prohibited, 164 
Foscolo, Ugo, 192 

GALILEI, family of the, i 

Livia (Galileo's daughter), 73, 

191. 195, 384 
Livia (Galileo's sister), 33, 66, 

Michelangelo, 33, 67, 99> 216, 

Vincenzio (Galileo's father), 2, 

I3> 33 

Vincenzio (Galileo's son), 30, 73, 

190, 197, 202, 215, 223, 231, 305, 
340, 38?, 398 

Virginia (Galileo's sister), 32, 66 

Virginia (Suor Maria Celeste), 

73, 190-336 passim; death, 338 

Galileo, birth and early youth, 4 ; 
youthful abilities, 6; enters on 
medical studies at Pisa, 8 ; observa- 
tions on the pendulum, 9; con- 
structs the pulsilogia, 10 ; takes up 
mathematics, 12 ; leaves Pisa for 
Florence, 14; constructs hydro- 
static balance, 14 j studies centre of 
gravity in solids, 17, 22 ; lectures 
on Dante's ''Inferno," 18; first 
visit to Rome, 19 ; seeks a professor- 
ship, 18-20 ; appointed professor in 
Pisa, 21 ; discovers the cycloid, 22 ; 
attitude towards Aristotle, 22 ; 
writes "De Motu Gravium," 24; 
experiments on falling bodies, 24 ; 
resigns professorship, 26; literary 
works, 28-32 ; sister's wedding 
present, 32 j appointed professor in 
Padua, 34 j early writings in Padua, 
37; declares for Copernicanism, 319 ; 
serious illness, 40 ; invents machine 
for raising water, 42 ; constructs 
geometrical and military compass, 
42 ; appointment as professor re- 
newed, 46 ; reputation spreads, 47 ; 
at home, 47 ; friends, 49; constructs 
air-thermometer, 51 j lectures on 
new stars, 53; appointment as 
professor renewed, 56 ; experiments 
on loadstones, 59 ; on the sympa- 
thetic needle telegraph, 63 ; rela- 
tions with the Medici family, 64; 



Galileo [continued] 
dabbles in astrology, 64 ; family 
affairs, 66 et seq.; constructs the 
telescope, 74; appointed professor 
for life, 78 ; first telescopic observa- 
tions, 85 et seq.\ distributes his 
telescopes, 98 ; reception of his 
telescopic discoveries, 100; Horky's 
attack, 106; observations on Saturn, 
1 08; quits Padua for Florence, 1 16; 
contemplated writings, 118; ap- 
pointment at Court of Tuscany, 
121 ; observes phases of Venus, 
I2 3 t goes to Rome, 126 ; observa- 
tions on Sun-spots, 128 ; on lunar 
mountains, 133 ; the moon not 
habitable, 134; discourse on float- 
ing bodies, 136 ; gathering storms, 
146 ; polemical letter to Castelli, 
149 ; denounced to the Inquisition, 
1 52 ; polemical letter to Grand 
Duchess Cristina, 157 ; goes to 
Rome, 158 ; admonished by 
Cardinal Bellarmine, 163 j recalled 
to Florence, 170 ; treatise on the 
tides, 171 ; proposes his method for 
rinding longitudes, 172 ; ironical 
letter to Archduke Leopold, 179; 
observations on comets, 181 ; writes 
" II Saggiatore," 183; metaphysics, 
1 88; his children, 190; moves to 
Bellosguardo, 192 ; his eldest 
daughter, 193 ; goes to Rome, 
200, 204 ; Papal pension, 206 ; 
explains and constructs the micro- 
scope, 207 ; reply to Ingoli, 211 ; 
begins his Dialogue on the two 
systems of the world, 214 ; family 
worries, 215 ; threatened loss of 
salaried leisure, 225 ; goes to 
Rome with the Dialogue, 229 ; 
moves to Arcetri, 235 ; difficulty 
as regards Imprimatur^ 239; plan 
and contents of Dialogue, 243 ; 
Dialogue denounced, 265 ; before 
the Inquisition, 270 et seq. ; sentence 
and abjuration, 312 et seq.; exiled 
to Siena, 331 ; retirement to 
Arcetri, 338; depression, 340; 
behind the scenes, 342 ; publishes 
Dialogues on the New Sciences, 346; 
contents of Dialogues, 349 ; value 
of, 366; resumes longitude pro- 
posals, 372; moon's librations, 375; 
blindness, 378 ; sad condition, 381 ; 
moves into Florence, 382 ; makes 
his will, 383 ; returns to his 
"prison," 386; visited. by Milton, 
388 ; Viviani joins him, 391 ; con- 
troversy with Liceti, 391 ; last 

words on Copernicanism, 393 ; 
designs pendulum -clock, 396 ; last 
days and death, 400 ; burial, 402 ; 
monument, 404 ; translation of 
remains, 406 ; relics, 407 ; tempera- 
ment and tastes, 408 ; obiter dicta^ 
412; greatness as a teacher, 413; 
tribune of Galileo, 413 ; tercen- 
tenary of birth at Pisa, 417 ; ter- 
centenary of professorship in Padua, 
417; bibliography, 423 

Gilbert, William, 59 ; the earth a 
magnet, 62 ; hazy notion of gravi- 
tation, 62 ; Galileo's appreciation 
of, 258 

Grant, Robert, on value of Galileo's 
work in mechanics, 370 

Grassi, Orazio, attacks on Galileo, 
182, 213 ; concedes Galileo's great- 
ness as teacher, 413 

Gravitation, Gilbert's idea of, 62 ; 
Galileo's idea of, 250 

Gravity, centre of, in solids, 17, 22 

of air, 350 

Gregory, James, designs reflecting 
telescope, 95 

Griemberger, 127, 132; admits Jesuiti- 
cal origin of Galileo's persecution, 

Guicciardini has Galileo recalled from 
Rome, 170 

Guiducci, Mario, discourse on comets, 
181, 327, 384 

HABITATION of moon and planets, 


Hariot, Thomas, Sun-spots, 132 
Harris, Richard, pendulum-clock, 


Harrison, John, his chronometer, 173 
Harvey, William, student in Padua, 


Henri Quatre, 99, 108 
Hiero, story of his crown, 14 
Hobbes, Thomas, and Galileo, 390, 

Horky, Martin, attack on Galileo, 


Huygens, Christian, on the telescope, 
80 ; on planets' satellites, 105 ; dis- 
covers Saturn's ring, 115 ,* con- 
structs pendulum-clock, 399 
Hydrostatics, 136 et seq. 

" IL SAGGIATORE," 183, 186 et seq. 
Inchofer, Melchior, 270, 297, 343 
Ingoli, Francesco, 211 
Inquisition, 153-171, 270-326; also 

frequent references in subsequent 




Inquisition, extra judicial pressure, 
300, 306 

proceedings not ratified by 

Pope, 273, 322 

unjust and illegal, 276, 323 

sentence, were Judges unani- 
mous ? 321 

Irradiation, effects of, 88, 133 

JACK, PROFESSOR, 37, 360, 371 
Jansen, Zacharias, invents microscope 

and telescope, 76, 209 
Jesuits, the, 121, 129, 186, 265, 284, 

342, 345, 425 
Jupiter, 89-92 

KEPLER, 39, 55, 65, 94, 104, 122, 

212, 259, 363 
Kuffler and the microscope, 209 

LAGALLA, 135, 413 
Lagrange, 136,^348,370 
Lamp, Possenti's, in Pisa, 9 
Landucci, Benedetto, 32, 66, 218 
Lecture-desk, Galileo's, in Padua, 57 
Libri, Julius, 101 
Liceti, Fortunio, 327, 391 
Light, velocity of, 362 
Line of quickest descent, 356 
Lipperhey, Hans, invents telescope, 


Loadstone, 61 
Longitude, proposals for finding, 172 

et seq.y 372 et seq. 
Lorini, Father, denounces Galileo, 

153 ; contemptible excuse, 1 60 

MACHINE, dredging, de Medici's, 26 

for raising water, Galileo's, 42 

Maestlin, 39, 54, 88, 105 
Magalotti, Conte Filippo, 263, 265, 

267, 273 
Magini, Giovanni Antonio, 18, 35, 

Magnetic needle, 59 ; magnetic needle 

telegraph, 63 

Magnetism, 59 et seq. , 258 
Malatesti, the poet, 30 
Mars, 125 

Marsili, Cesare, 263, 331, 413 
Mathematics, low estimate of, 10, 13, 


Mayer, Simon, 46, 107, 132 
Mazzoni, Jacopp, 26, 40 
Mechanics, Galileo's work in, 37, 348, 


Medals, commemorative, 62, 96, 404 
Mellini, Cardinal, 153-154, 163 
Mercury, 126 
Metius, James, and the telescope, 75 

Micanzio, Fulgenzio, 50, 270, 344, 

346, 376 ; 423 
Michelangelo, 4, 13 

the younger, 126, 279 

Microscope, 207 et seq. 
Milton, John, 5, 30 

and Galileo, 125, 388 

Montucla, J. F., 343, 371 

Moon, Galileo's observations on, 86, 


Hbrations of, 375 

not habitable, 134 

Moons of Jupiter, 89, 119 
Morosini, Francesco, 283 
! Motion, accelerated, 355 

laws of, 367 

parabolic, 359 

projectile, 356 

uniform, 354 

MSS., Galilean, collected by Viviani, 

425 ; sold as waste paper, 427 ; 

subsequent recovery of, 428 ; 

recent extraordinary forgery of, 

Vatican, 168, 308, 321 

NEEDLE, magnetic, 59 

telegraph (by sympathy), 63 

Newton, 6, 9, 61, 95, 182, 360, 367, 

37*, 43i 
NelH erects monument to Galileo, 

405; recovers many Galilean 

MSS., 4^7 
Niccolini and his despatches, 271 

et seq* 

OPTICS, 88, 133, 362. Aha under 

Orsini, Cardinal, 171, 179 

PARALLAX, stellar, 253, 393 
Pascal, 214, 35, 43* 
Paul V., i2i, 127, 170 
Pendulum, vibrations of, 9, 26, 363 

applied to clocks, 396 

Pension, Papal, to Galileo, 206, 


Percussion, force of, 37, 366, 401 
Perelli, Tommaso, 407, 428 
Piccolomini, Ascanio, 331 
Pieroni, Giovanni, 347, 393 
Pierozzi, Father, epitaph over Galileo's 

grave, 404 

Pinelli, Gianvincenzio, 34, 36, 49 
Plague in Florence, 231, 240, 263, 


Plane, inclined, 25, 356, 369 
Planets, new, predicted, 255 
question of their habitability, 



Playfair, Professor, appreciation of the 

Dialogue of 1632, 261 
Poggibonsi, famous meeting- place, 


Ponsard, his drama " Galilee," 102 
Portraits of Galileo, 239 
Possenti, his lamp in Pisa, 9 
Problems, mathematical, 19, 214, 

366, 401 
Pulsilogia, 10 


RENIERI, FATHER, and the longitude 

papers, 374 
Riccardi, Niceolo, 183, 205, 226, 230, 

240, 272, 328 
Ricci, Ostilio, 12, 14 
Rimiccini, Francesco, 30, 393 

Tommaso, 200 

Roemer, on velocity of light, 363 
Roiti, Professor, measurements of 

Galileo's object-glass, 97 
Ruskin, John, 2 
Ruzzante (Angelo Beolco), 244 


122, 178, 245 

Salviati, Filippo, 131, 192, 245 
Santorio, 10, 53 

Sarpi, Paolo, 44, 49. 122, 148, 155 
Satellites of the planets, 105, 115 
Saturn's ring, 108-115 
Scaglia, Cardinal, 286, 288, 290, 322 
Schemer, Father, 105, 129, 265, 347 
Seggett, Thomas, 51, 104 
Serristori, Mgr., 264, 286 
" Sidereus Nuncius," 85-92 
Simplicio = the Simpleton, 268-9, 273, 

393> 322> 3 8 

Sirturo, Girolamo, and his first tele- 
scope, loo 

Sizzi, Francesco, 103, 106 
Sphere, Galileo's treatise on the, 39 
Stars, fixed, 88, 251-6 

Stars, rrew, 45, 53 
Sun-spots, 128-132 
Suor Maria Celeste. See Galilei, 

Virginia (Galileo's daughter) 
Sustermans, the painter, 238 

Targioni-Tozzetti, 416; on Galileo's 

MSS., 427 ; on translation of 

Galileo's remains, 406 
Tasso, 29, 411 

Telegraph, sympathetic needle, 63 
Telescope, 74-97, 109 

binocular, 75, 175 

Thermometer, 51-53 

Tides, the, 62, 171, 179, 213, 259, 


Torre del Gallo, 237 
Torricelli, 22, 92, 94, 400, 417 
Torture, was it applied ? 3 10, 323 

stages of, 323 

Tower, leaning, Pisa, 24 

URBAN VIII., 127, 137, 148, 156, 
184, 200, 205, 213, 227, 229, 268, 
and after, passim 

VACUUM, nature's horror of, 349 

Vallombrosa, 4 

Vatican MSS., 168, 308 

history of, 321 

Venus, phases of, 123 

Verses of Galileo quoted, 31 

Virtual Velocities, principle of, 37, 
136, 371 

Viviani, Vincenzio, 8, 40, 208, 356, 
366, 391, 398, 404. See also Bib- 

WEDDERBURN, JOHN, 51, 106, 207 
Welser, Mark, 101, 129 
Willoughby, Richard, 50